"Lemon" is a song by Japanese singer-songwriter Kenshi Yonezu, released as a single through Sony Music Entertainment Japan on March 14, 2018. It is the theme song for the TV series Unnatural. It has sold more than 500,000 physical copies and 3,000,000 digital copies in Japan.^[1][2][3]

Kenshi accepted several interviews about "Lemon", talked about the background of "Lemon" and others. The temporary title was "Memento." He said, "I think it came from somewhere in my memory, but I can't really explain it well either." Even when the day before recording, he was still writing the lyrics, the last two sentences "Like one half of a fruit sliced in two, even now, you are my light" suddenly appears in his brain and he said, "Ahh, so this song really was "Lemon."" He also did the cover illustration himself. He focused on liveliness and freshness of a lemon, giving it an image quite unlike what's typically associated with death.^[4] For the song, he wanted to go for a ballad, but a simple ballad is not very interesting for him, and he did not want it to be purely gloomy. As a result, he made a hybrid of sorts, with sad words over a dancing, skipping rhythm.^[5] He made this song while on his nationwide tour, during which his grandfather passed away. He agonized over it a lot, so it took even longer to finish than usual.^[6]

On February 27, 2018, the music video was published on YouTube.^[7] It was filmed in a church and has over 800 million views, making it the most-viewed Japanese music video.^[8]

On December 31, 2018, Yonezu gave his first performance on television, singing the track on 69th NHK Kōhaku Uta Gassen.^[9]

Credits adapted from the liner notes.

• Kenshi Yonezu - production, arrangement, vocal, guitar
• Koichiro Muroya - string arrangement, strings
• Yu Suto - bass
• Masaki Huri - drums
• Ichiyo Izawa - piano
• Tatsuya Mochizuki - guitar technician
• Koji Imamura - drum technician
• Akira Miyake - vocal direction
• Masahito Komori - recording, mixing
• Ted Jensen - mastering