When Isao Komori moved from the Gunma countryside to the bustling city of Tokyo for college, he believed this to be an opportunity to start his life anew. Yet as months pass, Isao comes to realize that he hasn't made a single friend. Despite the time spent as a serious student, Isao drops out during his sophomore year to become a shut-in, killing time playing video games.

Isao's only saving grace is going to his local convenience store every day to see "The Angel of the Convenience Store," a high school girl named Mari Yoshizaki. Though Isao is content watching her from afar without confronting her, one day she turns to meet his eyes. Without being able to remember a thing, Isao awakens in the body of Mari. Unsure of how he found himself inside Mari, or where the young lady he now possesses really is, Isao chooses to continue Mari's life in her place.