Mina, who has a tomboyish and straightforward personality, is currently living with her boyfriend. Their life together seems to be going well… but her boyfriend is unreliable and weak, and Mina secretly feels anxious. She has to take the lead in sex, and he doesn’t want to go to work. She loves him, but he’s the complete opposite of her: effeminate. “I wish I’d been born a man…” One day, Mina wakes up with a strange feeling in her crotch. She cautiously turns over the covers to find a healthy, erect penis…!?