The young volunteer surgeons Katsuhiko Aoki and Kōichirō Shimada travel to Kenya to assist Dr. Murakami in his studies at the Institute of Tropical Medicine as well as in his treatment of locals. They are then sent for a month to Lokichogio to perform surgery on child soldiers and Kōichirō is so moved by his experience that he later asks to return to Lokichogio, where he is joined by Wakako Kusano.
Kōichirō had previously had a relationship with Takako Akishima in Nagasaki and had invited her to come with him to Africa but she chose to remain with her family to eventually take over her father's medical practice. Prior to that, Kōichirō had stuttered in high school but was able to overcome it when he sang as a soloist in the school choir.
An injured child soldier named Ndung'u is brought to the hospital in Lokichogio and Kōichirō operates on his leg but the boy is left using crutches. Ndung'u is very distrustful of others and his only intention is to return to life as a soldier. Kōichirō leaves the city to get supplies and Ndung'u is certain that he will not return. When Kōichirō returns, Ndung'u is surprised and reconsiders his plans for the future. He begins using his artistic talents to draw portraits of the doctors. After Kōichirō dresses up as Santa Claus and hands out Christmas presents to the children, Ndung'u decides to become a doctor to atone for his past crimes.
Kōichirō decides to stay in Lokichogio instead of returning to Japan. Wakako privately sets up an orphanage. Takako takes over her father's practice. While attempting to visit an old patient, shots are fired at Kōichirō's vehicle and he is killed by a grenade.
After the 2011 Tōhoku earthquake, an old woman whose illness was treated by Kōichirō visits the orphanage and donates a small bag of corn kernels to the people suffering in Japan. Ndung'u travels to the Tōhoku with the kernels and befriends an orphaned Japanese boy.
