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 has a typically bizarre visit to her hometown over winter break, but even that weirdness isn't enough to prepare her for what's going on back at Midorigaoka Academy--someone is impersonating Super Bun to do evil deeds! Can the Public Morals club unmask the creepy doppelganger before Super Bun's reputation is permanently destroyed?!