High school senior Heita Fukai (Takeru Sato) doesn't know what to do with his life. Having been seriously ill until recently, he never had the opportunity to think about his future. He leads a mundane existence among his classmates, all of whom are struggling with their own issues. There's the popular guy with secret hang-ups, the boy who can't afford the tuition, the girl with bulimia and the pathologically shy kid. The teachers don't fare much better. The high school is a microcosm of our troubled modern society.

One day Fukai stumbles across a mysterious and attractive new girl in school, Q10 (Atsuko Maeda), whom he soon finds out is actually a robot. Assigned by the principal to be her mentor and told to keep her true identity a secret, Fukai tries to teach Q10 about human feelings. In the process, he becomes aware of his own complex, emotional makeup. Fukai realizes that he is learning about life from an android, and that he may be falling in love with her.