While cleaning her son's room, Reina becomes engrossed in a pornographic magazine that was left out, and her hand reaches for her crotch. Reina is absorbed in the immoral pleasure, when her son's friend, Kosuke, comes to visit... Reina invites Kosuke over to her house to wait until her son comes home, but once her body is aroused, she craves a man. "Kosuke, do you want to do something naughty?"