Natsuki, a wife who cannot give up on having a child with her husband who became impotent in an accident. After much discussion, the couple has come to the conclusion that "surrogate sex with her father-in-law, Kiyoshi." He thought it would be easier to show his love to him than to a complete stranger, but in front of the young and beautiful Natsuki, Kiyoshi regains more energy than he should! It was supposed to end with a simple sexual encounter, but Kiyoshi relentlessly pursues Natsuki's body, saying "You must be lonely because you can't do it with him..." Under the pretext of having a child, he unreservedly cums inside his son's wife many times for his own benefit. Natsuki also becomes addicted to "sex with her father-in-law, approved by her husband"...