Takashi's father's new wife, Kaori, is as close to his son Takashi as an older sister or a younger brother. Moreover, her figure is outstanding, and her sexy, firm buttocks are particularly stimulating for Takashi, who has been deprived of women. Takashi can't help but stare at her sexy buttocks whenever he has a chance, not only while she is doing housework, but even when she is asleep, and he even fantasizes about rubbing oil on Kaori's buttocks and rubbing his penis against it and giving her a handjob. But then he can't stand the fantasy alone...