Junichi Naruse, an ordinary man with a passion for art, decides to resume drawing and painting. In the process, he meets and falls in love with Megumi Hamura. After they begin dating and eventually decide to live together, Junichi visits a real estate office. However, while trying to save a child during a robbery, he is shot in the head. Junichi regains consciousness a month after the incident. His miraculous recovery is made possible by a brain transplant from an unknown donor. As time passes, Junichi notices drastic changes in his personality, which affect his relationships as he struggles to maintain them. Gradually approaching the brink of insanity, he attempts to figure out the cause by determining who the donor is before losing sight of his own identity forever.