Satoshi, asked to fetch soap for his bathing mother Yoriko, is captivated by her enormous breasts. His mother's body, which he hasn't seen since childhood, is more stimulating than he imagined, and he involuntarily reacts in his groin, getting kicked out of the changing room by Yoriko. However, Satoshi can't forget the sight of Yoriko naked, and while fantasizing about his seductive mother jerking him off, he ends up masturbating…
