Mafuyu is the no-nonsense, take-charge and hard-hitting leader of her high school gang. But when she gets expelled for being a delinquent, her mother, fed up with her daughter's wayward ways, sends Mafuyu to an isolated school far off in the country.

Mafuyu's plan to be an ordinary student seems to be working out so far. She's got a friend (Hayasaka) and a plan to join a totally normal school club (crafts). But homeroom teacher Mr. Takaomi has something different in mind--he wants Mafuyu to take down the notorious leader of the campus gang!