Funasaka Touma is approached by his homeroom teacher with a recommendation for a slightly unusual school. The school introduced is "Toyoashihara Academy," a national boarding school that does not accept general student applications and admits only by recommendation. It’s said to be the alma mater of his teacher, with low tuition and a dormitory system that seems like a perfect opportunity, prompting Funasaka to decide to enroll. However, the academy harbors a vast dungeon underground and is a place where sex and violence reign, far removed from common sense. Though Funasaka is initially bewildered,