Satoshi, a boy who was asked by her mother Mariko to fetch soap while taking a bath, is fascinated by her huge breasts. Since she was a child, her mother's body is more stimulating than I imagined, and her crotch reacts unintentionally, and Mariko drives her out of the dressing room. However, Satoshi, who can't forget Mariko's nakedness, masturbates while having a delusion of being squeezed by her bewitching mother.