Riku is a high school sophomore in the middle of his adolescence at a boarding school. Riku is in the throes of adolescence in his second year at the boarding school. He has a crush on his teacher, Toyama, but he doesn't have enough courage to admit he's gay... Then one day, one of the students suddenly disappears! Riku and his roommate Okajima, a delinquent but trusted leader of the students, and his roommate Otomo, an honor student, are trying to solve the mystery, but...?