At Nana Mi's self-defense class, a male student named Tokugawa arrives, boasting some experience in martial arts. Dismissive of self-defense techniques, he intends to overpower Nana Mi and prove his strength. During a private lesson, Tokugawa suddenly grabs her chest, prompting her to instinctively throw him down. Rather than apologize, Tokugawa smirks and reappears before her, issuing a new challenge.