Iroha, who lives with her daughter and son-in-law, was feeling frustrated. That was because she had heard the sounds of their lovemaking. It was a good thing that her daughter and son-in-law got along well, but it was a poison for Iroha, who slept alone. Iroha 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-righteous, but one day, when Iroha witnessed her daughter-in-law masturbating in the living room, she invited him and had sex with him. A few days later, she received a report that her daughter was pregnant. Although it was a happy thing, Iroha also began to think that she would like to become pregnant with her son-in-law's sperm...