Six months have passed since he welcomed the young and stylish Miyu into his home as his stepmother. His adolescent son has begun peeking into the bath. One day, he peers into the bathroom through a gap in the window and sees Miyu masturbating with complete concentration. The image of Miyu's lustful body is stuck in his mind, and he can no longer suppress his desire. Miyu refuses at first, but after experiencing the pleasure of a powerful sexual intercourse that is left to her youth, he gradually begins to give in to her...