The husband, Hajime, wanted a child with his wife, Chihaya, but discovered that Chihaya couldn't conceive. To avoid being disliked by Hajime, Chihaya asked her mother, Reika, to act as a surrogate mother. Although confused, Hajime obeyed his daughter Chihaya's desperate request and began having sex with Hajime to try and conceive! What was supposed to be just sex to create a child turned into a climax when Hajime, with his enthusiastic lovemaking, brought him to orgasm, ignoring Chihaya, and he himself experienced an orgasm during penetration!