Souichiro Nagi and Bob Makihara arrive at Toudou Academy, planning to rule the school by defeating anybody that get in their way just as they have done at their previous schools. They soon learn that this is no ordinary school when Maya Natsume flings Souichiro out of the school window. Souichiro crashes through the roof of the Juken Club and sees Aya Natsume naked while showering. She then kisses him and proposes out of the blue, much to his embarrassment. Although Aya is adhering to the ancient Natsume tradition that the women in the family would marry the first man they revealed themselves to, this causes much annoyance for Souichiro.