Iruma Suzuki, a fourteen year old Japanese boy incapable of refusing polite requests, works hard to support his scumbag parents. He is suddenly kidnapped to the Netherworld by the demon Sullivan after Iruma’s parents sold his soul. Sullivan wishes to adopt Iruma as his beloved grandson, since his friends always boast about their grandsons and he is jealous. Iruma reluctantly agrees and is enrolled in the Demon School, Babyls, where he must keep his human identity secret or risk being eaten by his classmates. Iruma attends the opening ceremony and learns Sullivan is the school's director. First Year Representative Asmodeus Alice tries to give his speech but Sullivan makes Iruma do it instead. Iruma reads a speech provided by Sullivan, terrifying and impressing the students as the speech was actually a dangerous spell to prevent Iruma falling or embarrassing himself. Asmodeus challenges Iruma to a duel for insulting him but Iruma, having been raised by his scumbag parents who constantly put him in dangerous situations, has developed an almost superhuman ability to dodge attacks. The other students assume Iruma refuses to fight back because he considers Asmodeus weak. When a girl in the audience is almost hurt, Iruma saves her, but the effects of Sullivan's spell prevents him falling forwards and he accidentally knocks Asmodeus unconscious by throwing him backwards in a German Suplex. The story spreads throughout the school, making Iruma famous. Iruma is shocked when Asmodeus happily declares himself Iruma's servant. Sullivan is delighted Iruma seems to have a bright future in the Netherworld.

During breakfast with Sullivan, Iruma demonstrates his ability to consume truly shocking amounts of food. He tries to refuse to attend demon school but decides to go when Sullivan reveals he has bought even more thoughtful gifts for him. Asmodeus informs Iruma they must summon their magical familiars and the strength of the familiar will determine their demonic rank and which class they are placed in. Their advisor, Naberius Kalego, immediately dislikes Iruma for being Sullivan’s grandson. To summon a familiar the students perform a ceremony using their blood on summoning parchments marked with Naberius' demonic seal to prevent cheating. Asmodeus summons a fire breathing Gorgon snake. Iruma tries a summoning but as he has no demonic power in his blood, the familiar summoning accidentally becomes a demon summoning using the power of Naberius' demonic seal, causing Naberius to be summoned as Iruma's familiar in the embarrassing form of a small, cute, fluffy owl with bat wings and horns. Despite it being an accident, the other students assume Iruma must be even more powerful than Naberius to be able to bind him as a familiar, thus increasing Iruma's fame even more. Sullivan happily informs them familiar summoning contracts are unbreakable and last an entire year. Naberius becomes bedridden from shock and Iruma's rank is left undetermined. Iruma meets a hyperactive student named Valac Clara whom Asmodeus warns Iruma not to speak to.

Asmodeus explains Clara is a weirdo who people try to avoid. Clara becomes attached to Iruma who is compelled to play with her after she says "please". Clara reveals she possesses magical pockets which can copy any object she sees. Iruma learns other students have been manipulating Clara into creating free food for them. Clara sadly reveals she has gotten used to having to bribe people to be her friends. When she tries to bribe Iruma he refuses, upsetting her, until Iruma explains he wants to be her friend without bribes. This makes Clara so happy that when the other students try manipulating her again, she throws a drinks machine at them before using Asmodeus as a target for paint dodge ball.

Iruma is unsure if Asmodeus and Clara are his friends since he never had friends before. Iruma learns a student's rank controls what food they can order. Clara gets in trouble with the snack stall owner who considers her replicating pockets a form of shoplifting. Naberius arrives to settle the matter only for Clara to trick Iruma into summoning Naberius, turning him back into an owl. Iruma, Clara, and Asmodeus flee while the stall owner traps Naberius and demands payment for the shoplifted items. Iruma asks Asmodeus and Clara if they are his friends but is surprised to learn demons have no concept of "friends", but they agree to be friends anyway. Sullivan holds a faculty meeting where it is decided Iruma, Clara, and Asmodeus will all be placed in the Misfit Class for Problem Children.

Sullivan reveals to Iruma he put him in a class of troublemakers to help him not stand out, along with Asmodeus and Clara so he wouldn't be alone. Iruma immediately runs afoul of booby traps set by his new classmates who wagered on whether he would survive. Iruma meets Sabnock Sabro, a tall muscular delinquent who plans on becoming the next Demon King. Iruma learns there are ten demonic ranks, with Yodh, or 10th Rank, being strongest, and the Demon King is always chosen from among the Yodh. Sabnock admits he was placed in the Misfit Class for trying to fight a teacher. Naberius arrives and sets them a task to determine their ranks, a race through a dangerous valley, though Naberius warns them to avoid the guardian beast that is in a particularly foul mood. Most students opt to fly, except for Iruma who has no demon wings and simply falls off the cliff when pushed by an impatient Naberius. Sabnock flies straight for the guardian, hoping to defeat it and get a high rank. Iruma is carried off by demonic crows that accidentally drop him in the guardian's nest with its baby, who is injured. Iruma tries to help the baby and discovers his human blood can heal demon's injuries instantly. The grateful baby decides to fly Iruma to the flag as a thank you. Elsewhere, Sabnock admits he made a mistake trying to defeat the guardian as it easily overpowers him.

Sabnock reveals he wants to become Demon King to prove himself better than his pacifist older brother. Iruma suddenly lands in front of him, pacifying the guardian by showing its child is healed. Sabnock assumes Iruma is somehow powerful enough not to be afraid of the guardian. At the finish line, Asmodeus places first and Clara, riding on Asmodeus' shoulders, comes second. Iruma and Sabnock end up in last despite riding on the guardian's back. Naberius explains a Rank Owl will provide everyone with rank badges. Sabnock declares Iruma his rival. Asmodeus earns Dalet, 4th Rank, Clara earns Gimel, 3rd Rank and Sabnock earns Bet, 2nd Rank. Iruma, instead of a badge, receives a golden ring. A startled Sabnock recalls a prophecy, that the next Demon King will make other demons his servants, heal injuries with his blood, have been born a foreigner, and wear Solomon's Ring. Iruma freaks out when a black flame demon appears from the ring and starts draining power from his classmates. Naberius senses the ring threatening him and moves to sever Iruma's entire arm but is stopped by Sullivan who scolds him. Sullivan explains the ring is actually the Gluttonous Feeder Ring that eats magic power, then pacifies it by feeding it some of his power. Iruma's rank is undetermined and by default receives the lowest rank, Alef. Meanwhile, his taming of the guardian and his ring attacking his classmates increases his fame yet again.

Iruma's fame draws the attention of the student council. In Botany Class, the students learn to use magic to grow demonic plants. Sabnock produces a feral flower that eats everything it sees, Asmodeus an elegant flower with flaming petals, and Clara a mutated flower beyond rational description. Having no magic, Iruma says the spell as a joke while thinking of his home in Japan. Sullivan's magic suddenly bursts from his ring, just as Sullivan calls Iruma to explain that the ring lets Iruma use magic, but Sullivan had forgotten to set a limit on its output. Iruma's overpowered seed explodes into a giant cherry blossom tree, destroying the greenhouse. Student council president, Azazel Ameri, recognizes the tree as a human plant and suspects Iruma is human. Ameri privately reveals most demons believe humans do not exist, but her family secretly owns a library of sacred relics, i.e. Japanese manga, and is obsessed with the First Love Memories series, but as she cannot read Japanese has mistakenly concluded it is a manual of human love spells. Iruma tries to clean up the falling cherry blossoms, despite Clara making more mess. As he leaves Iruma turns a corner and accidentally knocks Ameri over. Recognizing the similarity to a romantic scene from First Love Memories, Ameri believes Iruma is trying to make her fall in love with him using human magic and concludes he must be human.

Iruma and Ameri end up frozen, unsure how to react. Iruma assumes Ameri is angry while Ameri assumes she is in a magical love duel. Ameri drops First Love Memories which Iruma recognises as a manga he helped illustrate to earn money. Ameri realises he can read Japanese and, rather than reveal he is human, drags him to her office and asks him to read the story out loud for her. After Iruma finishes, an embarrassed Ameri puts her number in his phone so she can ask him to read for her again. Iruma can't decide if he prefers his old life or his new life. Sullivan's servant, Opera, informs him it may be possible to visit the human world if he becomes a high ranking demon. Iruma is summoned by Ameri, making Asmodeus and Clara suspicious. Ameri decides, based on First Love Memories, that spending time with Iruma counts as a date. Asmodeus and Clara buy Detection Warding Glasses to hide while following Iruma. Asmodeus assumes Iruma is hatching a plan to take over the student council while Clara assumes they are excluding her from a new game. After learning about ambition from First Love Memories and listening to Ameri's plans for the future, Iruma realizes his pushover personality had prevented him from having any ambition of his own.

Asmodeus tries to stop Clara ruining Iruma's plans of taking over the school. Iruma struggles to come up with a dream so Ameri urges him to raise his rank as a temporary goal. Clara breaks into the room to take Iruma back, assuming Ameri was trying to steal him. As time passes and Iruma spends more time with Ameri, Clara becomes increasingly jealous, so Sabnock suggests she lure Iruma with her feminine wiles. As Clara has no feminine wiles, she joins the Seduction Class to learn sexiness, but the succubus teacher, Raim, determines she has only 2% sexiness, making her impossibly innocent. Clara tries to use seduction methods on Iruma but he assumes she is playing games. Clara becomes depressed but returns to normal after her mother kisses her forehead. The next day, Clara tries to use a kiss attack, but Iruma avoids it with his superhuman dodging skill, while Clara ends up receiving detention from Naberius. Clara admits she has zero sex appeal and resigns herself to losing Iruma, until Iruma innocently reveals he does think of her as a girl, restoring her confidence enough she declares she will make Iruma fall for her. Iruma feels an unusual thump in his heart as she pulls him along holding his hand. Raim happily observes that Clara's sexiness has risen to 10%. Iruma decides to get serious about raising his rank from Alef, 1st, to Bet, 2nd.

Iruma asks Asmodeus to help him climb the ranks and Asmodeus overreacts and begins planning to make Iruma a Yodh, 10th rank, and rule the school, though Iruma assures him he would be content with making it to Bet. Asmodeus agrees, assuming Iruma has a complicated reason for becoming a Bet, and explains the best way is to score well on an upcoming Rank Promotion Exam based on Execution Cannonball, a dangerous competition similar to human dodge ball. Iruma assumes he will do well with his ability to avoid danger until he realises the other students are allowed to use their demonic powers. He asks Sullivan for training and learns he can use his ring to use magic during the exam, but Iruma decides he wants to compete with his own power and not magic borrowed from Sullivan. Sullivan strengthens Iruma's hands to give him a fair chance then leaves the physical training to Opera. Iruma struggles to catch the ball as his instinct is still to dodge, but he refuses to give up and even gets help from Asmodeus and Clara. After a week, he still cannot catch the ball but Opera assures Sullivan Iruma is definitely having fun. Eventually, Iruma manages to catch the ball and Opera informs Sullivan Iruma is ready to take the exam.

The day of the exam arrives. Naberius explains their ranks will be increased based on the opponents they defeat, but only if they are on the winning team. Asmodeus is assigned to a different team from Iruma but decides to help him. The exam is instant chaos as Iruma's classmates use their powers while Clara floods the court with multiple balls. Iruma manages to catch the real ball, only to realise he never learned how to throw it. Sabnock, irritated that Asmodeus appears to be daydreaming, tries to strike him but Asmodeus strikes Sabnock out instead. Asmodeus continues to strike players out without thinking, until only he and Iruma remain. Asmodeus is put in a tight spot, if he lets Iruma win he would be helping Iruma gain a rank but also undermine all his hard work. After a moment of hesitation, he decides to throw with his whole power. Ameri arrives to watch the exam for herself. Iruma overcomes his fear and catches the powerful throw, but as he cannot stop it he instead spins in a circle to redirect the balls momentum back at Asmodeus who is struck out by his own power. Naberius, impressed by Iruma's tactic, promotes his rank to Bet, 2nd. Ameri congratulates Iruma on finally gaining an ambition. Iruma thanks Opera for all his training, upsetting an emotional Sullivan who realises he did very little to help Iruma at all.

A new teacher, Balse Robin, begins teaching the Misfit Class about the importance of bonding with one's familiar. Asmodeus and Sabnock summon their Gorgon snake and Kelbie horse and Clara summons her Falfal, a rare familiar whose actions are mysterious. Iruma tries to refuse, until Balse says "please", so Iruma summons a furious Naberius. Balse reminds Iruma he needs to control his familiar, according to the rules written by Naberius. Naberius decides to make Iruma the best summoner in class, even though it involves playing embarrassing games to promote trust. Iruma sincerely apologises so Naberius asks why Iruma didn't summon him to fight the valley guardian. Iruma explains it was so neither Naberius nor the guardian would get hurt. Asmodeus and Sabnock get in a fight so Naberius defeats their familiars and angrily informs the students that familiars are powerful, violent monsters only kept in check by their contracts. The best summoners should trust their familiars while also fearing them, as Iruma does. Naberius also forces Balse to rethink his teaching style.

Iruma learns about the Battlers, groups of students with similar interests who form groups to help each other raise their ranks, like school clubs. Iruma decides to join one of the Battlers to find a new goal and possibly raise his rank again. Asmodeus tries to prepare Iruma as the senior Battlers begin their Rookie Hunt, an insanely terrifying stampede by older students to recruit first year students into their groups.

As the hunt begins most seniors try to recruit Asmodeus. The hunt is so brutal the first years are put in actual physical danger. Ameri and the student council monitor most of the mayhem while Iruma realizes that Ameri is actually the student council president. Ameri surprises everybody by inviting Iruma to join the council's Battler. Naberius announces a three-day trial period where students can try numerous Battlers before deciding which to join permanently. Clara shows repeated interest in Raim's Succubus Battler. Iruma struggles to decide as his fame means he is invited to join every Battler. His ring suddenly activates and drags him through the air, dropping him on Ami Kirio, the recruiter for the Magical Apparatus Battler, whose necklace is made from the same metal as the ring. Iruma visits several Battlers, most of which are dangerous in some way and unsuitable. Sullivan alters Iruma's ring so he can choose the level of magic he wants to use, Devil, Demon, or Ifrit, and a level for emergencies only, Pandoroola. After testing the ring at the Execution Cannonball Battler, Ameri texts Iruma, reminding him to visit the council Battler before the trial period is over. Iruma is caught up in an explosion caused by one of Kirio's apparatus.

The council members are confused over Ameri's sudden enthusiasm for Battler recruitment. Iruma texts her that he won't be able to visit the council after Kirio's explosion, but Ameri believes finding out she is the council president has scared him away. Kirio explains that he researches and creates magic items, but his magic power is so weak he cannot use the items he creates. His goal is to allow weaker demons to stand up to the higher level demons that mistreat them. Iruma decides to join his Battler and he is followed by Clara and Asmodeus. Iruma does later visit the student council, to Ameri's delight, at least until Iruma explains he joined another Battler.

With the trial period over, the school prepares for the Battler Party for Battlers to welcome their new recruits and meet their parents. Sullivan must attend the Thirteen's Dinner, a meeting of the Netherworld's thirteen greatest demons, all of whom are concerned the netherworld is falling to chaos without a Demon King, and believe it is time to raise either Sullivan, Levi, or Belial to the throne. Levi and Belial agree Sullivan should take the throne, but Sullivan refuses as he would have less time to spend with Iruma. Henri, one of the thirteen and Ameri's father, is forced to arrest Sullivan after finding evidence Sullivan illegally visited the human world.

Sullivan is questioned by Demon Border Control. Most of the first years panic at the thought of their parents visiting the school. Sullivan appoints Naberius as temporary school director while the rest of the staff wonders what Sullivan did to get arrested. Kirio reveals that all Battlers give presentations competing for prizes, maybe even a rise in rank, but the Magical Apparatus Battler has such a small budget they normally stand no chance, until Iruma is inspired to create fireworks. As the testing requires darkness, Kirio decides they must stay at school overnight. While trying to create gunpowder, Kirio reveals he has an ability to create magical barriers, the only reason he survives so many explosions. Iruma asks Ameri to loan him one of her manga so Kirio can see what a firework should look like, but she refuses, at least until she realises she would get to see real fireworks. After they successfully create fireworks, they exhaust themselves with a pillow fight, utilizing Iruma's dodge ability and Kirio's barriers. Kirio is later contacted by a powerful demon named Baal that can use lightning magic, revealing he is the reason Sullivan has been arrested and he has been plotting with Kirio to create a machine to destroy the school.

It is announced the Battler Party will last three days and the first place prize will be an increase in rank for the Battler members and an increase of two ranks for the Battler president. Kirio continues working on his machine, which flashbacks show he was only able to complete due to Iruma's help, and that his powerful demon friend plans to use his machine to kill as many students as possible. As Kirio works in his hidden workshop, he is suddenly interrupted by Iruma, who had been dragged through the air by his ring searching for Kirio's necklace. Kirio decides to reveal to Iruma that the secret workshop is hidden on the school roof behind one way, soundproof glass, and that his plan to help the weak stand up to the strong includes the school bell, which will be rung to begin the Party. Still not understanding Kirio's meaning, Iruma urges him to try and win first prize with their fireworks to prove they don't need to be strong to win. Kirio appears happy he and Iruma are so alike. With the preparations over, the Battler Party can finally begin, to Kirio's delight.

The Party Eve begins, a festival the night before the main competitions start. As fireworks require darkness, Iruma and the others decide to scout their competition. Iruma knocks the Yakisoba Battler out of the competition by devouring their famous Ogre sized serving, leaving them with no ingredients. Iruma is warned by his classmates that his main competitors are the New Magic Battler, who will attempt to conjure water from a stone, the Game Battler, with their Virtual Sorcery Hat to allow people to experience virtual reality adventures, as well as the Underwater Circus, and the Magic Beast Battles. Asmodeus reveals they will set off their main firework as the school bell rings to signal the start of the competition. Clara accidentally lights the fuse, but when it misfires they realise their biggest firework is missing. Kirio takes the stolen firework to his workshop. Meanwhile, Ameri's father possesses evidence of Sullivan kidnapping Iruma, given to him by Baal, the powerful demon helping Kirio. As the sun sets, Kirio destroys his necklace, covering the entire school with multiple barriers preventing people from being able to move around. Iruma finds himself separated from Asmodeus and Clara by a barrier while Kirio begins his plan.

Sullivan senses the barriers appearing. Iruma realises the barriers are Kirio's. Naberius finds the barriers are self-repairing, meaning they could only have been cast by a Tet, 9th Rank, and can likely only be fully destroyed by a Yodh, 10th Rank like Sullivan, meaning his arrest was arranged beforehand. Naberius manages to move by breaking barriers and moving through before they can repair and has another teacher announce to the students that the barriers are a surprise maze event by the New Magic and Game Battlers. Naberius begins researching all demons with barrier creation abilities. When most of the students make it to the courtyard easily, Naberius worries they were manipulated into going to the courtyard. Kirio loads the firework into his School Destroyer machine, but suddenly realises Iruma is heading to the lab, somehow finding his way toward Kirio even though he destroyed his necklace. A flashback reveals Asmodeus deduced Kirio must have been planning his attack for years and is now using a map of the school and one of Kirio's magical apparatus, copied by Clara, to guide Iruma through the barriers. Naberius identifies Kirio as the likely suspect and orders the teachers to capture him. Part of the school collapses and Ameri saves a student from being killed. Iruma finally reaches the lab.

Iruma reaches the workshop where Kirio reveals he plans to use the firework to destroy the school. Kirio reveals the Ami family are famous for their barriers and magical strength, but when he was born with weak magic, he was sent to the Garden of Delinquents for problem children. Despite being bullied he made a friend, but when bullies stole her earring and threw it in a river, Kirio tried to catch it with a barrier but failed, devastating her. That was when Kirio realised he perversely enjoyed watching people's despair. Baal, who believed demons are too nice compared to their society's evil past, helped Kirio plan to destroy Babyls as a symbol of their weakened society while Kirio plans on enjoying Iruma's despair when Clara and Asmodeus die. However, when Iruma seems unconcerned and calmly removes the firework, Kirio is confused. Iruma explains that thanks to his childhood, he almost never feels despair anymore. Kirio realises he and Iruma are not alike at all. Iruma unlocks his rings Ifrit mode to throw the firework into the sky, but it hits the barrier. With the explosion seconds away Iruma breaks a promise he made to Sullivan and unlocks the ring's Pandoroola mode, obliterating the barrier and exploding the firework in the sky where it delights all the watching students. With Iruma passed out, Kirio saves him from falling off the roof, and despite raging that his plan is ruined, he admits defeat and that Iruma is a better demon than he is.

It is revealed that as Iruma was talking with Kirio, Balse Robin used archery magic to shoot a warning note to Sullivan. Sullivan then broke out of prison and saw Iruma use Pandoroola to destroy the barrier, forcing Sullivan to save the school from falling debris. The teachers apprehend Kirio, though he does remind Iruma to beware of other demons wanting an evil society. He is taken by Demon Border Control to be interrogated. Sullivan shows Iruma that his firework was immensely popular with the students, though he is scolded by Ameri who wanted to watch the firework together. Iruma shares credit for the firework with Asmodeus, Clara, and Kirio.

As the Battler Party starts, the students vote for their favourite Battlers just as their parents turn up for the party. Iruma prepares the remaining fireworks before meeting 4 of Clara's 5 siblings and her mother, who are all as eccentric as she is. Asmodeus is caught by his embarrassing mother, Amuryllis, a Demon Lord of Seduction, who showers Asmodeus with love and affection. Sullivan and Opera arrive to attend the festival with Iruma, causing general chaos as they do. As the sun sets, they set off the fireworks and Iruma declares his new family to be his pride and joy before insisting on posing for a photograph with Sullivan and Opera. With the voting over the winner of the Battler Party is decided.

The Closing Spectacular begins with the handing out of prizes. The Succubus Battler receives an upgraded club room, the New Magic Battler a year's supply of black holy water, while the grand prize of rank increases is given to the Broadcast Battler. Naberius announces that, for unspecified reasons, an extra award has been created, the prize for which is one member of the Battler will go up by one rank. The winners are announced to be the Magical Apparatus Battler, despite being disqualified due to Kirio's schemes, with Iruma getting the rank increase to Gimel, 3rd rank. Iruma worries he has spent too much time standing out instead of hiding.

Ameri's father, Henri, takes an interest in Iruma. Ameri summons Iruma to read manga but rushes out after seeing her father. Henri confronts Iruma, not knowing why Sullivan is so attached to him. Henri tells Iruma he met a human once before and legally returned them to the human world. He begins to ask if Iruma wants to go home, but is interrupted by Ameri, who recounts all Iruma's recent achievements and claims he is an outstanding demon. Suspicious, Henri asks how Ameri knows Iruma and she awkwardly blurts out they spend time alone talking about love, shocking Henri into semi-consciousness. Asmodeus and Clara tell Iruma they know something happened with Kirio, but they are happy to wait for Iruma to tell them. Iruma decides he does not want to return to the human world and must work harder at hiding his human identity.

Iruma's rank increase gets more newspaper coverage than Kuromu, a dem-dol. Asmodeus explains dem-dols are vital as teenage demons go through an "evil cycle" of destructive behaviour, so they are distracted by popular entertainment which converts their impulses into healthy excitement. Kuromu is revealed to be Crocell Keroli, a quiet girl from the misfit class who is embarrassed by her cute idol persona. Despite her siblings being better academically, Crocell found that other demons treated her kindly because she was cute, so she became Kuromu to beat her siblings and earn a higher rank than her mother. However, since Iruma arrived he has been in the newspapers more often than her, making her jealous. At her next concert, she furiously realizes Iruma is in the audience, having received tickets from the Broadcast Battler. Coincidentally, Iruma wins a ticket to meet Kuromu in person. A furious Crocell struggles to keep her identity a secret, however, Iruma already knew who she was due to her distinctive hands. As her glasses contain identity detection warding, Crocell decides Iruma must be a super-fan to notice such small details, but is surprised when Iruma admits he is jealous of how well she manages to stay hidden as he is tired of standing out by accident. Realising that Iruma is more popular than her without trying only makes Crocell more upset and she passes out with a fever from overusing her ice magic.

Crocell’s manager, Mal, decides to cancel the show as cooling Crocell’s body back to normal requires a family member, none of whom will arrive in time. Ameri attends the concert with a ticket from her father, who is working security. Crocell has a nightmare about disappointing her family then wakes after she should have been on stage, only to realise Iruma saved the show by dressing as a girl and performing an opening act, with Clara and Asmodeus dressed as dem-dolls, in order to let Crocell recover. Ameri suspects the dem-dol on stage looks just like Iruma, but convinces herself it couldn’t be. Crocell realises Iruma, who hates standing out, was willing to go on stage to save her career and decides he isn’t so bad. She thanks Iruma for his help but then forces him to stay on stage performing for the entire concert. Afterwards, Mal tells Crocell her entire family actually came to help while she was asleep, making her incredibly happy. Mal also secretly reveals to Iruma Crocell’s family love her and have watched every concert on TV; they just cannot come in person because they also pass out when overexcited. Back at school, Crocell warns Iruma if he reveals her identity he will regret it. She also asks if they can still be friends, despite hating all the attention the female Iruma got in the newspapers.

Iruma predicts he will have a normal day. After breakfast with Sullivan, he watches Asmodeus and Clara race to school, has homeroom with Naberius, and attends normal lessons. After school he reads Ameri more manga, which contains lines about keeping secrets. Ameri remembers the female dem-dol who looked like Iruma and nervously asks if he has anything bothering him, and he says he does not. Then, when handing him a snack, she touches his hand and her heart beats wildly. Iruma goes home, has a bath, then dinner with Sullivan, then goes to bed, but suddenly realises he now fits into demon society, and worries it no longer bothers him. Iruma becomes unusually withdrawn as he considers the offer Henri made to erase his memory and send him home. Asmodeus and Clara decide food will cheer him up and sneak into the school kitchen, however they end up arguing and decide to both make meals and see which Iruma prefers. Clara misunderstands her mother’s claim love is the most important ingredient and lovingly crafts a bizarre meal, whereas Asmodeus decides on an elegant fish dish, despite having ichthyophobia. In the morning, Iruma finds both dishes work together to become even tastier. Asmodeus and Clara are forced to agree after trying both dishes and declare it a draw after becoming friends again. Though, a few minutes later, they are arguing again. Iruma finally decides he wants to stay in the Netherworld after all.

Iruma re-adjusts back into his everyday life at the school. As he heads for lunch, the beast that had previously emerged from his ring once again appears, however, to both their surprise, he can suddenly now talk, discovering himself to be the manifestation of the Gluttonous Feeder Ring. After chastising Iruma for his poor use of magical abilities, the beast gets him to use a transformation spell to give him a proper form, which ends up becoming a small, slender, one-eyed figure in a suit; he also tells Iruma to refer to him as "Alicred". He convinces Iruma to continue experimenting with his transformation abilities, eventually leading him to transform into his "Irumi" outfit. At this same time, Ameri finds him and is completely flustered and confused at the sight of Iruma in a dress, and runs off before he can explain himself. He wants to clear up the misunderstanding, but Alicred refuses to reveal himself unless they can prove there are more cases like him. Iruma tries to ask Sullivan for answers, but he brushes it off as nonsense. While doing research on the Ring, and figuring out the moments in the past when Alicred was conscious, Iruma figures out that the higher ranks he gets, the more Alicred changes. Iruma declares his new goal to continue rising the ranks to learn the truth behind Alicred, even if it means standing out more, and still failing to clear up the misunderstanding with Ameri.

Ameri has nightmares about Iruma cross-dressing. Crocell forces Iruma to wear his dress for a photograph as her fans are demanding to know who the idol was at her concert. During the struggle Ameri witnesses Iruma on top of Crocell and drags him away. She asks him about the Magical Apparatus Battler which, after the incident with Kirio, has been closed. She offers to reopen it if Iruma, Clara, and Asmodeus each obtain letters of recommendation from three Battler presidents. Clara temporarily joins the Gaming Battler, Asmodeus the New Magic Battler, and Iruma is forced to join the Student Council under Ameri. While carrying out student council tasks, Iruma starts to realise how capable Ameri is, especially when she refuses to let Sullivan continue spoiling him. Later, while reading First Love Memories together, Ameri’s teacup breaks, which she considers ominous. Iruma soon grows into his role on the council, impressing the other members, while Ameri considers whether to make him a real council member. Ameri is lured away and drugged by an unknown hooded person. Her absence is soon noticed by the council, and when they find her she begins acting strangely.

The student council learns that Ameri has been infected by a spell that, while retaining her old memories, has turned her into a much more dainty lady-like woman, and that she should return to normal if she keeps up her usual routine. However, the council finds themselves struggling to keep up with the workload Ameri can no longer handle, as well as unable to keep up appearances due to current her cutesy persona. They are then surprised by the sudden arrival of the one the council believes to be responsible for Ameri's predicament, the flamboyant president of the Disciplinary Battler, Ronove Romiere. He declares his intentions to take over the student council now that Ameri's no longer fit to run it, while playing coy when they ask if he put the spell on her. He challenges them to a "dissolution election", where the student body can vote on who should be the student council, and whoever loses must be dissolved. Iruma slaps his hand away when he starts touching Ameri, leading him to retreat, while the rest of the council praise him. The following day, Ronove uses his bloodline ability, "Charisma", to campaign, leading to a mixed reception until he promises to be more lenient/fun than the current student council, while Ameri struggles to keep up with her small support. Iruma decides to contact Clara and Asmodeus for assistance when Ameri asks him to talk. While waiting, Alicred reappears, telling Iruma the spell is nearly undone and just needs a trigger to completely fix it. Ameri then enters, facing Iruma dressed in her original student council attire.

Ameri had hoped her old outfit would trigger her return to normal but she now considers quitting the council to begin a peaceful high school life with Iruma. Iruma refuses and praises the hard work of her old personality. During the election, Ronove promises to make the school a pleasure paradise. Iruma's support reminds Ameri of how great she wanted Babyls to become, and she gives an impassioned speech imploring the students to pursue their own desires instead of Ronove's. Spotting Iruma in the crowd, Ameri realises she is completely in love with him, triggering her return to normal. Ronove denies cursing Ameri just as Clara and Asmodeus apprehend the real culprit, Eligoth Schenel, who created Ladylike Perfume to make Ameri cutesy to satisfy his perverted fantasies. After Eligoth is punished, Ameri invites Ronove onto the council. She also invites Iruma, but following her speech about pursuing his desires, he chooses to have the Magical Apparatus Battler reinstated, but also hopes to see Ameri at their next reading of First Love Memories. Alicred suggests the last trigger was difficult because Ameri secretly wanted Iruma to think she was cute. Ameri worries about acting normally around Iruma but finally decides to pursue her own desire to make Iruma hers.

Sullivan decides to throw a party and insists Iruma invite his friends. Iruma cleans obsessively when Alicred teases him about Clara being the first girl he invited over. Fearing he is not making a good impression as Iruma’s grandpa, Sullivan insists they play "Dark Parade" in the basement, which Iruma realises is the demon version of a test of courage. Sullivan sets up a fake monster he can defeat to impress Iruma’s friends, only for Asmodeus to defeat it first. After Sullivan grovels for help, Opera uses a 3D projector to fake a dragon, which Sullivan "defeats". They also find a chest containing a cake Opera made as the prize for winning the game. Sullivan is once again depressed when Opera gets more credit for the cake than he did defeating the dragon. After Clara and Asmodeus leave, Sullivan is cheered when Iruma thanks him for letting his friends visit. Iruma realises he still has a lot to learn about demon society, so Alicred decides to secretly help and magically changes Iruma's personality to resemble a teenage demon experiencing their first Evil Cycle of wanting to do evil deeds. The next morning Sullivan is horrified to discover his darling Iruma has become rude, ungrateful, and just downright evil.

Iruma's new personality leads his classmates to assume Iruma is in his Evil Cycle. When Iruma sees other students taking advantage of his fellow Misfit classmates, he confronts Kalego and demands they get a better classroom. Kalego claims there are no other available classrooms but Iruma demands the school give them the King's Royal Classroom, the classroom which the previous Demon King, Derkila, was a student in before becoming Demon King, now closed to honour his memory. Kalego is enraged at the suggestion so Iruma bets he can get the consent of every faculty member within three days, in which case Kalego will have to give them the room. Most of the Misfits claim they don’t actually care about the room, they only care about what is fun and best serves themselves, which Iruma points out is how real demons should be, egotistical, selfish, and evil, which is exactly why the Misfits deserve the King's Classroom the most. Inspired, the whole class agrees to help win the room. Iruma reveals he has a plan to get the faculties' consent, and he requires the help of Jazz, the Misfit’s notorious thief and pickpocket.

Iruma deliberately enrages Kalego allowing Jazz to pickpocket his diary, which they trade to Momonoki, an instructor with a crush on Kalego, for her consent. Clara gets the consent of Instructor Furcas in exchange for Schneider, the Misfits most intelligent student, assisting her research. Instructor Morax trades his consent for Kamui’s perverted knowledge. Picero and Goemon get consent from Instructor Stolas in exchange for clearing weeds. Iruma poses for a family photograph to get Sullivan’s consent. Instructor Orias wagers his consent in a game with Lead, the Misfit’s notorious gambler. Despite his luck boosting magic, Orias is affected by the magic of Elizabetta to show her favouritism and loses to Lead. Instructor Buer wagers consent on a duel with Sabnock who tried to duel him during the opening ceremony. However, Sabnock offers a sincere apology for his actions, shocking Buer that Sabnock has matured so much, and he gives his consent. Iruma decides to get additional consent from Ameri and the council, convincing her with a heartfelt speech about the Misfit's potential and sealing the deal with a wall slap that overwhelms her heart. After three days the Misfits easily collect all remaining consents except one, Kalego's.

Iruma confronts Kalego with the teachers' consent forms, but Kalego points out his agreement with Iruma used the word "Faculty", not "Teachers", meaning Iruma was supposed to get consent from everyone employed at Babyls like the janitors, chefs, and librarians. For his lack of critical thinking, Kalego claims Iruma is unworthy to inherit Derkila's classroom. Suddenly, all the other staff arrives with their consent forms, having decided to help Iruma in gratitude for helping all of them in the past. Defeated, Kalego furiously gives his consent as well. As the classroom has been sealed for centuries, massive crowds gather to see the classroom and the Misfits learn they have become famous. Kalego opens the doors with much ceremony, revealing the Classroom to be as luxurious as a castle with multiple floors, rooms, and expensive furnishings. Iruma takes possession of Derkila's old throne, shocking everyone into silence as he temporarily takes on the appearance of a true Demon King. The very next day, Alicred's spell on Iruma finally runs out, returning Iruma to normal, revealing him to be completely embarrassed. Iruma apologises to everyone at school but they don't care as they have become closer as friend. Everyone poses for a photograph with Iruma on Derkila's throne, including a furious Kalego.

Kalego informs the Misfits the "End of Terminus" (demon summer vacation) is approaching, but if they fail their exams they must attend supplementary classes during Terminus instead. Iruma reveals to Clara and Asmodeus he is bad at studying, plus while he can read the questions thanks to Sullivan’s spell, he cannot understand what the questions are about. Asmodeus decides they will form a study group, revealing anyone with a high enough score goes up a rank, but score too low and they could go down a rank. Ameri forces Eligoth to join the Magical Apparatus Battler as keeping an eye on him has become too time consuming for the council. Alicred is also worried, since his intelligence is based on Iruma's rank, so if Iruma loses a rank Alicred will revert to a mindless black flame demon. Asmodeus quizzes Iruma on the exam's five subjects and Iruma gets a perfect score on Mythical Zoology as every question is about humans and human society. Experiencing an unusual level of confidence from his perfect score, Iruma decides to take an elective class in Netherworld History taught by the Mythical Zoology textbooks author, Balam Shichiro, who is strange even by Netherworld standards.

Balam is obsessed with "Imaginary Creatures" that may or may not exist, like humans. While discussing how demons evolved wings, Balam notices Iruma doesn't seem to have any, until Alicred hurriedly transforms into miniature wings and attaches himself to Iruma’s back. Balam believes Iruma's small wings are a deformity and apologises for exposing them, revealing that he himself is abnormal as his mask conceals his scarred face. Iruma accidentally blurts out he is human and fears Balam will eat him, but instead Balam is happy to have proof humans exist and warns Iruma to be more careful in the future, making Iruma realise he is actually quite nice. Returning to class, Iruma finds everyone depressed over studying. Iruma, who always had to spend summer breaks working, is motivated by invitations to spend Terminus having fun with the Misfits. Balam appears and it is revealed he and Kalego were actually classmates years ago, and are still good friends. Seeing the Misfits struggling, Balam shows them different ways of studying, such as singing songs and playing games, and even creates educational picture books for Iruma. The Misfits begin helping each other and Iruma finds that studying has become fun. Finally, the day of the exams arrive.

Kalego informs the Misfits they all passed their exams, several of them have gone up a rank, and Schneider, the most intelligent, has gone up two ranks. Asmodeus claims without Iruma's influence most Misfits would have failed. Kalego congratulates Iruma on passing but it was not enough to go up a rank. Iruma informs Balam, who agrees Iruma seems able to influence people to be better. Kalego reveals Balam is the only other Khet, rank 8, apart from himself, and can sense lies which he uses to catch exam cheaters like Eligoth, though Balam does admit one student seems immune to detection.

Ameri invites Iruma to their usual manga reading, only for Clara to inform her Iruma is at karaoke with the boys, so she drags Ameri to a girl’s only tea party with Elizabetta and Crocell. Elizabetta insists on talking about relationships and Clara realises she might have a crush on Iruma and wouldn’t mind marrying him, causing Ameri to realise Clara might be a serious rival. After a brief argument over Iruma and love, everyone agrees to swap contact information and meet for another tea party. Iruma arrives to read manga to Ameri, but is thrown out as it is a girl’s only tea party.

Kalego is furious when Sullivan forces him to carry out home visits. Visiting Asmodeus' home, he learns his obsession with Iruma has caused him to neglect his younger sisters. Kalego determines Asmodeus should focus on himself more and could become a very powerful demon. At Clara's home, he is mobbed by Clara's siblings until Urara, Clara's most normal brother, calms everyone down long enough for Kalego to inform their mother Clara is a troublemaker with a good personality and a bright future, assuming she learns to think before she acts. The other visits go just as badly as he must duel Goemon's father, protect his wallet from Jazz's brother, and avoid marrying Lead's older sister. Arriving at Iruma's home, it transpires Kalego is terrified of Opera, who was his senior in high school and would torment Kalego to amuse himself. Kalego informs Sullivan Iruma has average grades and is always involved in major incidents, but has made many useful friends and has a natural ability to overcome challenges. Kalego attempts to leave but Opera tricks Iruma into summoning him in his cute owl form for amusement. As a result of the visit, Kalego gives the Misfits homework for over the holidays. Terminus begins and the Misfits invite Iruma to the Walter Amusement Park.

Iruma and the Misfits attend Walter Park, but Sullivan has insisted Kalego, Balam, and Opera attend as chaperones. Ameri also attends, mistakenly thinking it would be a date alone with Iruma. As the Misfits want to try different things they split into three groups. Kalego is pressured into funding a prize for the team that has the most fun, but insists those in third place receive double homework. Opera takes the girls; Balam takes Iruma, Asmodeus, Sabnock, and Picero, while Kalego takes Jazz, Goemon, Kamui, and Lead. The girls decide to force Ameri to buy a cute dress. Kalego's team decide to somehow force him to enjoy himself. Iruma sees Ronove who reveals Walter Park is owned by his father. Ronove also accidentally reveals the park's basement is Uraboros Prison, where imprisoned criminals secretly have their magic drained to power the park. It is revealed Kirio is in the prison and is working with a group of other inmates to escape, including outside assistance from the notorious Musashino Crew, an extremist group who believe demons should revert to being evil. Kirio had arranged to help them destroy Walter Park if they freed them from prison first.

Opera’s team have fun trying on dresses with Walter employees, Miki and Hyudarin. Kalego’s team take part in a shooting game with employees, Atori and Maemaro. Kalego’s team consider exploring Kiraragi Street but are warned by Kalego a battle once occurred there between demons during their evil cycles and even today it is a corrupt place where criminals gather. Coincidentally, Iruma gets lost down Kiraragi Street and is almost grabbed by a shady demon but is saved by a lady named Shiida. Despite her serious demeanour, she buys him ice cream and asks if he can show her how to have fun. Iruma helps her play with animals at the petting zoo and ride a ferris wheel. Eventually finding Asmodeus, Iruma tries to thank Shiida but she disappears. Iruma learns about Six Fingers, another criminal group wanting to revert to the old ways. Ronove removes Picero’s sleep mask and discovers he is almost impossibly beautiful. Ronove's servant, Wett, leaves and reveals he, Shiida, Miki, Hyudarin, Atori, and Maemaro are actually the Six Fingers planning to attack Uruboros and free Kirio. Wett sets off three magical items that summon three gigantic monsters to destroy the park, a Carmine Dragon, a Mountain Blue Minotaur, and a Panther Rat.

The monsters begin destroying the park. Kalego forces his team to fight Mountain Blue, even though they haven’t learned attack magic yet. By combining their various powers they manage to partially blind, distract, then attack Mountain Blue, but it has no real effect. Six Fingers infiltrate the prison to find Kirio and open all the cells to keep the guards busy. Vice Chief of the prison, Triton the Handshaker, who once broke a dragon’s neck with his bare hands, is defeated by Hyudarin, whose strength surpasses Triton despite being only a few inches tall. Jazz, having the highest rank, is put in charge by the others, despite his own fear. Jazz tries and fails to come up with an effective plan, until Kalego gives him a hint about the necklace Jazz always wears. Iruma is upset the day is ruined and begins to experience an unusual feeling. Several children are trapped by rubble and Iruma realises no other demons are willing to help, their natural selfishness preventing them helping unless it somehow benefits themselves, and they abandon the children with ease. Iruma finally realises what his unusual feeling is, an emotion he has never experienced before, anger.

Iruma rushes to help, even though it puts him in the way of Dragon, inspiring his classmates to help. Opera fights Rat with Ameri insisting on helping. Jazz and the boys manage to distract Minotaur long enough for Jazz to climb inside its ear. His necklace is revealed to be an Earpiercer Whistle which creates a sound wave that grows louder the more magic is put into it. Jazz creates such a huge sound wave it ruptures Minotaur’s ears. Kalego decides they have done enough and steps in, defeating Minotaur with a single move, which he admits was fun and agrees to pose for a victory photograph. Crocell sees the other guests panicking, quickly changes into her Kuromu persona, and puts on an impromptu dem-doll show to ease everyone’s fear. Ameri reveals her bloodline ability, Romantista, which increases her physical abilities the more she believes in herself. With her confidence boosted by Crocell’s song, she defeats Rat easily. Opera is so impressed he offers her a job working for Sullivan and Ameri is tempted as it would mean living in the same house as Iruma. Iruma and Picero save the children while Asmodeus and Sabnock prepare to battle Dragon.

Asmodeus and Sabnock become distracted arguing with each other while fighting Dragon. Dragon turns on Balam, Iruma, and the children, who only survive thanks to Balam. Asmodeus is distracted thinking Iruma is hurt, allowing Dragon to seemingly kill Asmodeus. Iruma is devastated until it is revealed Sabnock had saved Asmodeus. Sabnock is still willing to fight, having learned to surpass his limitations when Iruma saved him from the Valley Guardian, and scolds Asmodeus for being so concerned with Iruma he forgot to have ambitions of his own. Balam creates the giant wooden dragon Nigipnir and kills Dragon. Six Fingers sense the three monsters defeat and merge it into the larger Composite Magical Beast. Opera has Iruma summon Kalego in his owl form who teams up with Balam and Opera to defeat Beast. Kalego is devastated to learn that when in his owl form his familiar, Cerberus, becomes a puppy. Beast gathers its remaining magic to create a bomb to kill everyone in the park's emergency shelter. Unable to do anything in time, everyone is shocked when Ronove appears and uses his Charisma ability to force Beast to look at him, aiming the bomb away from the shelter and towards himself. Just as Ronove is about to die Iruma steps in front of him.

Iruma unleashes Alicred who swallows Beast's magic, defeating it for good. Kalego scolds Iruma for risking himself again but admits he did excellently. Opera understands why Sullivan chose Iruma as his grandson. Six Fingers reach Kirio and explain Lord Baal sent them. Kirio is overcome with emotion realising Iruma destroyed Beast and believes they are fated enemies. Baal contacts him, angry Walter Park still stands as its purpose to de-stress demons in their Evil Cycles is a barrier to his plans. Ronove's father puts the Misfits in a hotel as thanks for saving his park. Ameri approaches Iruma alone at a party, despite it looking like a romantic manga scene. Iruma tells her he is still unsure of his ambition but for now is happy to work to keep having fun. Ameri asks Iruma if, one day, they can do something together, just the two of them and despite being interrupted by Clara and Asmodeus, Iruma agrees, causing Ameri to pass out. The attack is mentioned on the news and Iruma becomes a hero overnight, causing the hotel to be swarmed by reporters and admirers. As it is unsafe to return home, Clara invites them to her house instead.

Iruma is surprised as he has never been invited to a friend's house. Arriving they find Clara's mother and siblings going overboard to welcome Clara's first friends. Their home is filled with strange objects apparently sent home by Clara's father, a professional adventurer. Clara is embarrassed when Iruma is shown her baby picture album until he remarks that she was super cute. It is explained that the family collects their food from the surrounding Hubbub Forest. Clara and Asmodeus try to compete over finding the best ingredients for Iruma, so Clara’s mother suggests hunting the Shabbu-Shabbu from Collateral Cave, the most delicious beast in the forest. Clara praises Iruma as the Hero of Walter Park, causing Asmodeus to consider if he actually helped at Walter Park at all. The Shabbu-Shabbu is a strange monster made from both animal and vegetable parts. It almost eats Clara's brothers but Asmodeus saves them and Clara's mother arrives and catches the Shabbu-Shabbu. After dinner, Clara is revealed to be excellent at singing relaxing bedtime songs. The next morning, Clara's mother secretly adds more photos to her album showing Clara has continued to grow up. Meanwhile, Ameri's father, Henri, flies towards Clara's home.

Henri informs Iruma he can return home but turns furious when Iruma asks about Ameri. Ameri plans a perfect date and arranges to meet Iruma privately at Aqua Case, an aquarium/swimming pool, but Iruma remains oblivious it is a date. Ameri’s plan fails repeatedly; due to her greater height she cannot hold Iruma’s hand because they're too far apart, and Iruma can't hold her from behind on the water slide because of her taller height means she has to ride behind him instead. Iruma buys gifts for everyone, including Clara which makes Ameri jealous and worrying the date isn’t exciting enough. They attend the fortune telling show where Mako, a water dragon, psychically picks ideal romantic partners. Unfortunately, the water has washed off the perfume hiding Iruma’s human scent so Mako tries to eat him. Ameri defeats Mako, ending up with Iruma in her arms. Ameri becomes depressed her plan was a total failure until Iruma notices a cut on her leg. Despite the embarrassment, Ameri claims it hurts to walk and wants to be carried, so Iruma uses magic to make the taller Ameri light enough to carry in his arms, making her realize that despite her plans' failure, it was the best date ever.

Iruma finishes the extra homework assigned by Kalego for losing the Walter Park competition. Sullivan and Opera take him shopping and while buying books, Sullivan purchases a copy of prophecies about the Demon King. Many people wonder why Sullivan still hasn’t taken the throne so Iruma asks about the Demon King. Sullivan remembers how Derkila, the now missing Demon King, was a lot like Iruma. Sullivan explains about the Thirteen Crowns, the leaders of the Netherworld like Sullivan. To become Demon King requires the support of all thirteen, but it is a heavy responsibility as the Demon King is the Netherworld itself and his power over it is absolute and can remake it any way they see fit, explaining current Netherworld society is simply the way Derkila wished it to be. Sullivan even remarks he would be interested to see what would happen if Iruma became Demon King, something Iruma seems quite concerned about, especially later after reading the prophecy scroll. Alicred summons himself and berates Iruma for forcing him to swallow all Beast's magic and then largely ignoring him ever since while enjoying himself. As the new term begins Kalego informs the Misfits unless they all achieve Daleth, 4th Rank, they will lose their right to use the Royal Classroom.

To help the Misfits achieve Daleth, Kalego has invited personal tutors for them. Jazz and Alocer are given fire demon Sergeant Furfur, who promises to make them the craftiest demons. Goemon and Picero have water demon Vepar, who promises to train them to have the strongest bloodline abilities. Elizabetta and Clara have Raim, who promises to make them the most charming demonesses. Crocell and Kamui have gentleman Mr. Hat, who promises to make them the greatest users of summoning magic. Sabnock and Asmodeus are given Balam, who promises to make them the strongest warriors. Iruma and Lead are given Balse, who only promises to train their fighting spirits. Ameri reminisces about her date with Iruma but is upset she did not manage to see him before school started. She is further disappointed when, due to his lessons with Balse, Iruma is forced to cancel their reading of First Love Memories, but she accepts it is necessary. Balse explains that while he planned their lessons, they will actually be taught by his cousin, Barbatos Bachiko, who unlike Balse is loud, violent, and cruel, and only bothering to teach them since Sullivan asked her personally. She immediately begins training by hurling abuse at them, forcing them to obey her every childish demand, and even forcing them to wear dresses for her amusement.

Lead decides to ask Balse to tutor him, but Iruma stays with Barbatos. She reveals to Iruma no one else has put up with her abuse this long before and his stubborn instinct to please other people makes tutoring him pointless. Iruma decides to try harder to become Barbatos' ideal errand boy. Later, the Misfits discuss their hellish training. Goemon and Picero reveal Vepar submerges them so they almost drown. Balse forces Lead to play video games without sleep to increase concentration. Asmodeus and Sabnock battle Balam constantly and have many injuries. Jazz and Alocer are missing after Furfur took them somewhere mysterious. Clara and Elizabetta strike sexy poses for hours, and Crocell and Kamui are forced into cages with their summoned creatures. Sullivan visits Barbatos to ask about Iruma's progress and it turns out Barbatos was having so much fun abusing Iruma she forgot to start his actual training. She reveals to Iruma her weapon, a bow that shoots 100 arrows with perfect accuracy. Most demons have too short an attention span to learn but she is confident Iruma can learn to shoot and even advance beyond Daleth. Seeing Iruma is eager to learn, she takes him to create his own weapon at the Magical Apparatus Battler, unaware Iruma is the battler's de facto president after Kirio's departure.

Barbatos shows Iruma her bloodline ability lets her create bows from any material, but Iruma will need a power core for the spell. Iruma selects a feather from his friend, the valley Guardian Beast. Barbatos warns him the next exam, the Harvest Festival, is a battle for survival, and unless he can create a bow tailored to his desires, he will fail. Barbatos recalls her heartache over her past students who failed or quit, and doubts Iruma will succeed as he seems to have no desires at all. Goemon and Picero evolve their bloodline abilities to escape Vepar's water cage. Crocell and Kamui form better relationships with their creatures and become stronger Summoners. Lead begins beating Balse at games, showing his improved concentration. Sabnock and Asmodeus learn to cooperate and strike Balam. Elizabetta masters sexy posing, but Clara masters sexiness through purity, the rarest sexiness. Iruma thinks hard about his desired bow, until Alicred points out thinking hard is the problem; desires are instinctive and above all, selfish. Thus, he demands Iruma's most selfish wish, which Iruma reveals is to heroically reach Daleth. Iruma successfully creates a winged demonic bow so perfect it fills Barbatos heart with hope again. With every Misfit having proven their potential for Daleth, the tutors move them on to the next stage of training; more weeks of hellish suffering.

After these several weeks, Barbatos decides Iruma is ready, but as his bow only has two arrows she insists he choose the right moments to use them. The Harvest Festival arrives; a hunt to gather food ingredients from a dangerous forest. Theft and betrayal is encouraged since students are graded as individuals, not as teams, but physical fighting is forbidden. Winners are said to have great futures, with past winners including Ameri, her father Henri, and Balam. The Misfits' weeks of hellish training have left them beaten up and yet emanating terrifyingly demonic auras. Asmodeus is gleeful at seeing Iruma again while Clara has concealed herself inside a fluffy animal suit and says nothing to anyone. The festival time limit is 6666 minutes; roughly 4.5 days, and ingredients can be submitted to referees to earn points at any time. Inside the forest, most students gather the easy ingredients for 10 points each. Asmodeus and Sabnock plan to hunt boss class monsters worth 3000 points each and share the points. However, there is also a legendary ingredient, the Legend Leaf, worth 100,000 points no one has ever found. Their plotting is interrupted by the Dorodoro brothers, Ichiro and Niro, skilled warriors forced to repeat their first year for being notorious rule breakers, who offer to compete for the boss monsters.

Ichiro and Niro declare if they win they will retrieve their Master Sabnock and Asmodeus stole from them. Crocell and Kamui use their improved summoning to make monsters gather ingredients for them. Allocer uses his intelligence to identify only the most valuable ingredients and teams up with Jazz to con other students out of their points. It is revealed during their training Furfur actually ran up a huge debt to the Demon Mafia then sold Jazz and Allocer to them as payment. They were forced to work in a casino, surviving by learning to anticipate peoples' intentions and then manipulate them. Every day Furfur would challenge them to a coin toss for their freedom and always won with Jazz certain he was cheating but never seeing how. After three weeks they realised the point wasn’t to identify how Furfur was cheating, it was to win by cheating him back. They won the next coin toss with a dirty trick, but Furfur had anticipated their cheating and somehow still beat them, but offered them a chance to play another game with him if they win the Harvest Festival. Meanwhile, Sullivan watches with some concern as many students plan to ambush Iruma, and yet Iruma appears to calmly wait for them to try.

The audience are confused to see Iruma sat eating his gathered ingredients with Lead. Balam explains to the audience Iruma is actually doing the right thing; the Festival lasts four days and most demons will exhaust themselves exchanging ingredients for points and then lose when they pass out from hunger, so by eating first then gathering points later, Iruma may actually win. Made a survival expert by his harsh childhood, Iruma teaches Lead how to thrive in adversity. The students planning to ambush Iruma leave since he has left no ingredients for them to steal. Lead finds he is actually enjoying himself but laments the lack of girls to talk to, referencing the fun they had when they attended a mixer with Sabnock, Jazz, and girls from other classes. Elizabetta and Clara in her costume abruptly appear. Clara drags Iruma away while Elizabetta charms Lead out of his secret ingredient stash without even resorting to her new sexy powers. It is revealed during her training Elizabetta wished for the skills to find a man to truly love. Once alone, Clara drags a surprised Iruma inside her costume, trapping them both inside, and declares Iruma as successfully captured.

Clara reveals her magical pockets have evolved into a dimensional space called Toy Box, filled with every toy and game imaginable. Iruma childishly can't resist and they play games for hours. Privately, Clara reveals she plans to finally make Iruma fall in love with her. It is also revealed Toy Box is designed to drain the "victim's" magic to function, but Clara finds her magic is draining faster than Iruma’s, meaning she is already in love with him. She confesses she loves him, but Elizabetta suddenly opens the costume, ending the spell and revealing it is already night. Iruma wonders what might have happened had Elizabetta not interrupted. As Clara and Elizabetta depart with their stolen ingredients, Iruma and Lead develop a new respect for the power of female demons.

As night falls, many exhausted students find themselves becoming victims of the more dangerous ingredients and quit the competition in a panic. Many students even require referees to rescue them as the ingredients' various magical abilities leave them incapacitated. One monster ingredient chases several girls into a castle and wake up Picero, who had been sleeping inside. Without his customary sleep mask the girls see his beautiful face and fall instantly in love.

Picero explains he used his ability, My Area, to extend his bed into a whole castle, but is extremely angry Goemon is letting people inside. The girls realise Goemon and Picero are on the edge of a serious fight. More students try to enter so Picero fights with Goemon over letting them in. Goemon rescues them anyway so Picero, feeling guilty, lets them in and the girls relax with the fight over. However, Picero starts another argument when he sees Goemon has rescued dozens of people.

The tutors hold a drinking party with Sullivan, Opera, and Barbatos. Mr. Hat is proud Crocell and Kamui have earned 14,200 points through monster taming. Raim is proud Elizabetta and Clara have earned 9400 by manipulating the boys. Vepar is proud Picero and Goemon have earned 8200 by hunting from the safety of their castle. Furfur is proud Jazz and Alocer earned 12,800 by theft and cunning. Sullivan and Barbatos insists Iruma is the likeliest to win, even though Iruma and Lead currently have zero points. In the forest, Lead is certain Elizabetta has feelings for him while Iruma is confused by Clara's confession. The tutors get drunk and pass out. In the forest, all the students sleep for the night, except Asmodeus, Sabnock, and the Dorodoro brothers who battle a giant monster.

The Dorodoro brothers demand their master back, goading Asmodeus and Sabnock into their challenge. The two pairs battle a Flapple Bird worth 10,800 points. Niro is a master strategist and Ichiro is fully combat proficient, a perfect team, while Asmodeus and Sabnock argue constantly. The brothers are revealed to have a bloodline ability, Peacock of Provocation, that makes enemies lose their temper, so they provoke Sabnock to attack them to disqualify him from the festival. Asmodeus stops him in time, exposing their ability. The brothers explain their dream to be warriors almost got them killed when they joined a battle totally unprepared. Their master rescued and trained them but suddenly left to become a teacher. Asmodeus and Sabnock assume they mean Balam, but it is abruptly revealed their master is actually Furfur; they never bothered to confirm who Furfur was tutoring, assuming it would be the strongest of the Misfits, Asmodeus and Sabnock. Asmodeus loses his temper and reveals Balam gave them secret pills to trigger his Evil Cycle at will, increasing his power and his repressed evil side; unimaginably elegant and savage. The Flapple is defeated and despite their desire to see Asmodeus disqualified, the brothers must dodge his attacks to avoid death. Sabnock snaps Asmodeus back to normal with a programmed password, the closest thing to Asmodeus' heart; Iruma. Back to normal, they argue over who gets the most points from the Flapple. The brothers can't believe they were defeated by two people with such poor teamwork.

The referees announce it is now day two of the festival. Lead is convinced Iruma is planning to find the Legend Leaf; Iruma is so surprised by the suggestion he agrees without thinking. As no student has ever seen the Leaf, Iruma wonders about asking the monsters themselves, leading them to Crocell and Kamui. They find her new authority over animals has almost put Crocell into her Evil Cycle, styling herself Queen of Monsters with Kamui as her Majordomo. In exchange for wearing dresses and dancing while Caroli takes pictures, her monsters reveal the Leaf has not even grown yet and give a riddle concerning the location of the seed and the vase it must be grown in. The watching tutors are impressed as this is the first time a student has found the riddle. So many students begin to quit from exhaustion, so the referees bring in the student council to help rescue them. Ameri is convinced Iruma will be the one to finally find the leaf. A council member teases Iruma might give Ameri the Leaf's flowers in a bouquet, sending her into a daydream of dating and marriage. Ameri discovers a gambling den of forfeited students wagering on who will win. She investigates and finds the ringleaders are two Misfits who forfeited suddenly and inexplicably; Jazz and Allocer.

Jazz and Allocer reveal they fell prey to student Orobas, whose bloodline ability Trauma made Jazz see nightmarish visions of his selfish brother Rock. When Jazz attacked Rock, he actually attacked Orobas so both he and Allocer were disqualified. Allocer informs Ameri Orobas is specifically targeting the Misfits to disqualify them. As the riddle contains multiple clues, Iruma and Lead take half the riddle each and split up. Iruma discovers the cave that should contain the seed, but Alicred worries about Iruma's ability to defend himself alone. Iruma discovers Naphula the Silent, a notoriously smelly student trapped by vines. Alicred suggests leaving him but Iruma rescues him. Reaching an underground temple they locate the seed only to narrowly dodge an attack by the seed's giant guardian, Toto the Genie. Toto informs them to earn the seed they must either defeat him in battle or tell him something interesting. Iruma and Naphula are stumped as Toto knows everything there is to know about the Netherworld. Iruma realises Toto is ignorant about humans so he, Alicred, and Nephula perform scenes from First Love Memories that Toto becomes obsessed with. Toto awards them the seed then demands Iruma's phone number so Iruma can tell him the rest of the story later.

Iruma decides to share his points with Naphula, noticing also that Naphula's stench no longer bothers him. Finding their way out of Toto's temple, Iruma is abruptly met by his selfish human parents, who announce they have returned to begin taking advantage of Iruma again. He is so terrified by their return he slips and falls into a chasm. Orobas, who had used his Trauma to give Iruma nightmarish visions, is satisfied by Iruma's supposed death but leaves Naphula unharmed since he is not a Misfit. Iruma, injured by his fall, suffers another vision of all his friends rejecting him for being a human and of Sullivan trying to return him to his parents. Despite knowing the visions are fake, he is paralyzed by fear of them coming true and losing his friends. A vision of Barbatos appears, but it only reminds him of the life threatening lessons she taught him. His courage returned, Iruma summons his bow and uses one of his two shots to shoot and destroy the visions, ending them. With renewed determination, Iruma decides to become the best demon he can and prove it to everyone by winning the festival.

Now on the festivals third day, Kalego reveals whoever wins the festival will receive the title Young King, a potential successor to the Demon King. He also reveals one student still has 0 points. The Misfits panic as they realise it must be Iruma, but Asmodeus and Clara still believe in him. With his injured leg Iruma cannot climb the chasm walls, but Naphula appears and uses a fast growing vine to grow a ladder. Iruma still cannot climb with his injured leg, but he suddenly remembers how his human blood healed the Valley Guardian's baby. Adding a drop to the vine, it grows so explosively fast and enormous it breaks through the ground and towers over the entire forest, shocking the students and teachers. Iruma declares he still intends to win but Kalego angrily reminds him he still has 0 points. Meanwhile, Lead has retrieved the Vase of Endings, having defeated his own Genie by winning 100 difficult games. The referees announce the vase by itself is worth 20,000 should Lead want to betray Iruma, but the announcement also makes Lead a tempting target for other students. Lead attempts to hide while searching for Iruma, but runs into the seductive Elizabetta once again.

Iruma finds Lead crying, revealing that Elizabetta robbed him of the Vase, not by seducing him but by telling him he is not her type and she doesn't like him, causing him to faint from shock. Knowing Elizabetta wouldn't be so needlessly cruel, Iruma suspects it was another hallucination, meaning Orobas stole the Vase. Lead confirms this with his training enhanced Sense Steal, learning the real Elizabetta is miles away in a secret hot-spring with Clara and Crocell. Crocell wishes to form a team with Elizabetta and Clara to invade Picero and Goemon's castle, steal their ingredient stockpile and claim the Young King title for herself. Picero, having no interest in fighting, decides to surrender to Crocell, but all the students sheltering in the castle decide to fight back. Having been trained in Gentleman Combat, Kamui leads the monsters in battle but they are all defeated by Goemon's enhanced Wind-Sword technique. Kamui summons boss class monsters as reinforcements and the battle continues. Nearby, Iruma, Lead, and Naphula watch the chaos in confused terror.

Orobas trades the vase for 20,000 points, putting him in the lead. The castle repels the monsters so Elizabetta begins charming the male students to take them captive, while Clara disappears on her own. Iruma, Lead, and Naphula meet up with Elizabetta and confirm Orobas is targeting the Misfits. Crocell lends them her Blizzard-Wolves to find Clara when they realize Clara is his next target. Orobas, who has consistently been stuck in 2nd place and assumed to be a part of a cult that worships "The Second", is unbearably jealous of the Misfit's popularity and abilities, so wants to be better than them by becoming Young King. He briefly feels guilty over using Trauma on them, but his partner Ocho mentally manipulates him into forgetting his guilt. Orobas gives Clara visions of Iruma telling her she is annoying and only talks to her for her ability to provide free snacks, like the bullies she used to deal with. Iruma arrives and furiously destroys the vision with his last remaining arrow. Orobas is so angry he prepares to use his strongest level of Trauma to break their minds for the rest of their lives, but Asmodeus appears from nowhere and stops him.

Asmodeus is disqualified for attacking Orobas, but proceeds to knock him out anyway and warns him he will return and kill him if he further harms Iruma or any other Misfit. The three agree to enjoy their reunion properly once the Festival ends with Asmodeus planning a party at his house. Ocho secretly retrieves Orobas, confident that with the Vase already submitted no one can stop Orobas becoming Young King, offering him extra rare plants for good measure. Iruma refuses to surrender, certain there is still a way to win, when out of nowhere, the referee Orobas submitted the Vase to re-appears, revealing himself to be Allocer in disguise. Allocer explains that while Jazz was disqualified for attacking Orobas, Allocer himself never attacked anyone, instead he posed as being disqualified to get access to the cameras watching the competition while still being a competitor. With help from the disqualified, they plotted revenge and have now stolen the Vase, robbing Orobas of victory. Allocer returns the Vase to Iruma, placing all the Misfits trust in hm. As the competition is almost over, the remaining Misfits are all proud of their high scores. With the Vase and the Seed in hand, Iruma and Lead are ready to grow the Legend Leaf.

Naphula uses his watering can to water the Leaf, but it also requires vast magic to grow. Iruma considers using Ifrit mode, but Alicred's magic is too drained. Clara gives the magic she accumulated from her Toy Box back and the Leaf blooms into an anticlimactic goofy face, just as the Festival ends; right as the Leaf bloomed, Iruma receives a vision of the Demon King Derkila. Clara and Naphula refuse their points so Iruma and Lead receive 50,000 each. However to everyone's surprise, Orobas is announced victor with 58,000, yet still feels unsatisfied by this. But then, Jazz suddenly points out the Leaf is worth 100,000, but the Vase is worth a separate 20,000. The judges confirm this, meaning Iruma and Lead actually receive 60,000 each and are the joint victors, reducing Orobas to third place. Orobas is content as this still breaks his curse of always coming in second place, and also helps him realize his hatred of the Misfits was masking his jealousy of their friendships. He apologizes to the Misfits and is forgiven by the whole school. Ameri reveals Naphula is a student council member and saving him from the vines was the secret third task to grow the Leaf, as only Naphula held the Rainbow Watering Can necessary for it to bloom. The Leaf, who can speak, reveals the tasks to make him bloom were actually tests of character to find the least evil demon to become the Young King. To honour the Young King, he announces a prize for every demon in attendance.

The Leaf explodes, turning the forest into Cherry Blossoms as a permanent monument to the Young Kings. Iruma and Lead are promoted to Dalet, 4th rank. Orobas, Sabnock, and the Dorodoro brothers are promoted to Gimmel, 3rd rank, for their impressive scores. Picero and Goemon achieve Gimmel for protecting students in their castle. Crocell and Kamui achieve Gimmel for their success taming monsters. Elizabetta achieves Bet, 2nd rank, for the potential she showed as a powerful demoness. Barbatos praises Iruma on his success, while Lead is disappointed as Robin is nowhere to be found. At the afterparty, the Dorodoro brothers finally learn Sabnock and Asmodeus' master isn't Furfur. Orobas can barely remember his partner Ocho, who also somehow avoided the broadcast cameras. Iruma and Lead are given front-row thrones, with Iruma grabbing Clara and Asmodeus, refusing to let go. The rest of the Misfit Class join them in celebrating, where Crocell feels mortified by the things she did as the Monster Queen. Kalego is concerned by Orobas' amnesia and who manipulated him, but is distracted when Iruma summons him, in his fluffy owl form, so the Misfits can celebrate with him. After the conclusion, everyone returns home to their parents. Sullivan has something important to tell Iruma but delays until after celebrating his victory.

The Babyls teachers go out for drinks to celebrate, including Kalego forced by Balam to join. Robin, who is hosting the party, seats Momonoki next to Kalego, on whom she has a crush since he mentored her as a trainee. All the teachers agree Iruma is definitely the most impressive student. Robin shares his opinion students are like family, only for every teacher to ominously disagree; students are a treasure teachers must protect. Anyone who threatens that treasure will receive "Discipline". A flashback to the end of the festival reveals Ocho was an infiltrator from the Second Faith, a cult that worships the number 2, and that he manipulated Orobas into believing his curse of always coming in 2nd place was an omen. Robin, on Kalego's orders, found and shot Ocho non-fatally as a warning to the cult. Ocho reports to his master, Baal, about all he learned about the Misfit Class, including Iruma who he snuck a recording bug on. They discover through the recording device that Iruma is a human and Kiriwo, now Baal's subordinate, salivates with joy at this revelation that he will plunge Iruma into ultimate despair by eating him. Baal confirms the demon world will soon become very interesting. Meanwhile, Kalego and Balam leave it up to the unfortunate Robin to get the drunk teachers home safely.

Iruma visits Lead's home to play video games together. The two decide to stop using the honorific "boku" (casual friend) and begin using "ore" (close friend) instead. Lead reveals an erotic magazine to get Iruma to talk about what girls he likes, causing a commotion that accidentally awakens Lead's terminally unmarried sister, Shakky. Upon seeing Iruma she attempts to charm him but is banished to her room by Lead. Shakky is actually impressed seeing Lead is becoming a responsible adult who values his friends. The two boys then proceed to argue with each other over who is the "little brother" in their relationship.

Iruma has resumed reading First Love Memories with Ameri again, beginning with a chapter on cooking. Ameri decides to make Iruma sweets as congratulations for winning the Harvest Festival and is dumbfounded when Iruma invites her to his house to cook. Opera is shocked to learn both Iruma and Ameri are abysmal cooks and steps in to prevent them poisoning themselves. After a harsh ordeal that leaves Opera mentally scarred, they are able to bake simple cookies. Iruma plans to give his to his friends and is surprised when Ameri gives hers to him for winning the festival. For his own safety, Opera point blank refuses to let them attempt to cook more complicated meals.

After inviting Barbatos over for snacks, Sullivan reveals to her several high-ranking demons have been kidnapped by the Musashino Gang. He asks Barbatos to continue tutoring Iruma, then informs her Iruma is human. Barbatos is so shocked Sullivan offers to erase her memory, but she decides to keep the secret. Asmodeus invites Iruma and Clara to his home where Clara causes her usual chaos, until Asmodeus gloats that Clara is still Gimel, 3rd rank, so Clara gloats about playing with Iruma in her Toy Box. Iruma feels tremendous guilt he still hasn't told them he is human, when Asmodeus' mother, Amu, overhears his guilt about keeping secrets and assures him keeping secrets is not a bad thing, unless he feels he can't be their friend without telling them. Iruma instead tells them how much their friendship means to him, including how much they both truly helped him during the Harvest Festival. Privately, he hopes to tell them the truth one day. Back at school, the Misfits prepare for the Music Festival, their last chance to get all remaining Gimel's promoted to Dalet, as well as the Bet, 2nd rank, Elizabetta. However, Kalego shockingly reminds them of their other classmate who is still only Bet: Purson Soi, who this whole time has gone completely unnoticed by everybody.