Reiko, who lives with her daughter and son-in-law, was in agony. That is because she had heard the sounds of their lovemaking. Although it was a good thing that her daughter and son-in-law got along well, it was poisonous to Reiko, who slept alone. Reiko woke up at night and witnessed her daughter and son-in-law having sex, and could not resist, so she comforted herself. She spent her days feeling self-loathing, but one day, when she witnessed her daughter-in-law masturbating in the living room, she invited him and they had a relationship. However, her daughter suspected her husband of cheating, and her relationship with Reiko ended. However, once Reiko's body was fired up, masturbation was not enough to satisfy her, and she avoided the hot sex with her daughter-in-law...