Rieko has been married for twenty years. When her son finds a job and thinks it's time to prepare for his old age, her son's company is exhausted physically and mentally by a black company, and he returns home as a cripple. Rieko is worried and calls out to her, but she is made to feel uneasy and she is in a bad mood. Rieko used to masturbate when her son wasn't around, but recently she couldn't and her body was aching. She then invited her husband to have sex with her for the first time in a while. She doesn't know that she is being peeped by her son. One day, Rieko was fucked by her excited son. From that day on her son...
