Fuutarou Uesugi is an ace high school student whose standoffish personality and reclusive nature have left him friendless, and his father is debt-ridden, forcing his family to scrape by. One day during his lunch break, Uesugi argues with a female transfer student who has claimed "his seat," leading both of them to dislike each other. That same day, he is presented with a golden opportunity to clear his family's debt: a private tutoring gig for a wealthy family's daughter. He accepts the proposal, but is horrified to discover that the client is the same girl he confronted earlier! After unsuccessfully trying to get back on her good side, Uesugi finds out that his problems don't end there since he must also tutor her sisters who, despite the very real threat of flunking, want nothing to do with a tutor. However, his family's livelihood is on the line so Uesugi pushes on, adamant in his resolve to rid the sisters of their detest for studying and successfully lead them to graduation.

Through their tutor Fuutarou Uesugi's diligent guidance, the Nakano quintuplets' academic performance shows signs of improvement, even if their path to graduation is still rocky. However, as they continue to cause various situations that delay any actual tutoring, Fuutarou becomes increasingly involved with their personal lives, further complicating their relationship with each other. On another note, Fuutarou slowly begins to realize the existence of a possible connection between him and the past he believes to have shared with one of the five girls. With everyone's feelings beginning to develop and overlap, will they be able to keep their bond strictly to that of a teacher and his students—or will it mature into something else entirely?