Mayu, who lives with her daughter and son-in-law, was tormented. 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 Mayu, who slept alone. Mayu woke up at night and witnessed her daughter and son-in-law having sex, and could not resist comforting 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. A few days later, she received a report that her daughter was pregnant. Although it was a happy thing, Mayu also began to think that she would like to become pregnant with her son-in-law's sperm...