A new sensation in school mystery featuring yuri and werewolves begins! At the private Shirai Academy, a boarding school for girls, young ladies receive higher education with the goal of becoming better brides. Students at this academy are not allowed to lose their "purity" for three years. If discovered, they will be immediately expelled from the school. In this academy, which is isolated from the outside world and has strict security measures, it was believed that nothing could take away the students' purity. Until the existence known as "werewolf" appeared among the girls——… A psychological battle to expose the culprit targeting the purity of a girl hidden among the 11 members of the student council!!