"I want you to be my sex practice partner!" Momoka, a childhood friend with a tomboyish personality, invites him to practice sex with her, holding a condom in hand, because she doesn't want to embarrass herself before her first time with her boyfriend. After the awkward sex practice, Momoka awakens to the pleasure of a penis. For three days while her parents are away, the two of them have sex all over the house, with their sexual desires completely exposed. After 11 ejaculations, he becomes addicted to condomless sex...