Hachimitsu Private Academy, once a prestigious all-girls school, has finally opened its gates to male students for the very first time. Among the lucky few admitted are five boys—Shingo, the brash foreign delinquent; Jo, the frail and eccentric one; Andrei, the large and awkward misfit; Gakuto, the brains of the group; and Kiyoshi, the most ordinary among them. Eager but hopeless at interacting with girls, the boys devise a daring plan to spy on their female classmates in the bath. Unfortunately, their scheme backfires spectacularly, exposing their perverted mission to the entire school. As punishment, the ruthless Underground Student Council sentences them to one month of prison life. But little do these strict enforcers know—the boys’ outrageous and shameless antics are only just beginning.