A high school student who has transferred to a new school finds his social life difficult until he notices an expressionless and solitary girl in his class. She is a loner who is unable to smile, but she secretly harbors a deep desire to learn how. Driven by a glimpse of a rare moment of happiness on her face, the boy, described as both stubborn and gentle, resolves to do everything he can to see her smile again. The story follows their unlikely connection as he tries to reach a girl who has shut herself off from the world, hoping to teach her an emotion she has never been able to express. The narrative focuses on the evolving dynamic between the persistent boy and the withdrawn girl as they navigate their way through a shared high school experience.