Mai visited her uncle's house one day. Mai, in the throes of puberty, is very interested in men's bodies and dicks, and she can't concentrate on her studies because she masturbates every day. "I'm a bad girl. I have to be punished..." Memories from her childhood resurface. My uncle who scolded me back then. Only my uncle can punish me... And then the masochistic training began. Her immature ass is spanked until it's bright red, her breasts that have begun to swell are tied up, and Mai awakens to the pleasure of being a total masochist.