When Hiroshi, who has been dating his girlfriend for six months, visits her house, he can't help but be drawn to her mother's busty curves. That night, Hiroshi is allowed to stay over at her house, and when he uses the bath, his mother washes his crotch, causing him to get an erection in the itchy air. Then, unable to fall asleep in the middle of the night, he leaves the room, and the soft curves of his mother's body come into view as she sleeps soundly in the bedroom. The young Hiroshi can't help but get excited, so he reaches out to touch his mother's sleeping form...!