The sisters Kotono and Suzuyo Miyatsuji attend Ikaruga Academy, where their mother, Kasumi, serves as the chairperson of the board. The man who captivates both beautiful sisters—Shoichi Kaneshiro. However, his attention was focused on the school nurse, Maiko Morizawa, and he became captivated by her body... Shoichi, who will be expelled if he doesn't pass the upcoming exam, is persuaded by Maiko to sneak into the principal's office and steal the disc containing the test questions. When Kotono witnessed the scene, Shoichi attacked her in the locker room as she was changing into her swimsuit, in an attempt to silence her.