St. Luminous Mission High School

Kaihei is an ordinary high school student who unexpectedly inherits the role of chairman at his late grandfather's all-girls school, St. Luminous Mission High School. Not only is he the sole male student on campus, but he’s also suddenly responsible for managing school affairs, enforcing rules, and handing out punishments. But when he arrives, he learns that a student has disappeared. With the help of his closest friends, Kaihei sets out to uncover the truth behind the mystery-without involving the police-before graduation day arrives.