Because his wife is pregnant and his mother-in-law is in the countryside, she helps the couple Ichiro. Being pregnant, Shiho is often irritable, she does not allow her husband to masturbate alone, making her suffer. Seeing that her daughter is a bit unreasonable, and her son-in-law is also pitiful, Sayuri decides to use her hand to help him release all the long accumulated 'discomfort'. But Ichiro has endured for too long, now being helped by a beautiful, seductive woman like Sayuri to satisfy his desires makes him unable to control himself. From using her hand, to using her mouth, and then using the vagina of his mother-in-law! At first, Sayuri also avoided it, but the pleasure that Ichiro brought successfully conquered her. Since then, every day Ichiro secretly has sex with his mother-in-law, and every time he ejaculates deeply into Sayuri's vagina. As a result, some time later, Sayuri told him that she was pregnant, and he would have to try harder to take responsibility for their two children...