The prestigious private Sakuraryo Gakuen, which has a 90-year tradition, has now lost its glory to the ground, and the back organization of the athletic club, the male “Black Warriors” and the female “Red Warriors”, have made use of them. One girl, Oda Yoko, who has transferred to such a school, sneaks into the principal's room to find out the truth of the death of her best friend, Atsushi Katayama.