Five male students join a school that was previously exclusive to female students. This boarding school transitioned from being an all-girls high school at the start of the new academic year. Accused of spying on the girls in the showers, the student council confines the five boys in a location referred to as the prison. The male students then face the challenge of breaking free from their confinement. ~~ Inspired by the manga series of the same title by Hiramoto Akira.