Mari Fujitani, a busty mother raising her son alone, struggles with her growing concern over his behavior. As he reaches adolescence, he repeatedly gropes her large, voluptuous breasts, unable to break free from his obsession. Every conversation quickly turns to her breasts, and he continues fondling them without hesitation. One day, the son catches his mother masturbating. After that, he begins groping her breasts from behind whenever she's doing housework. She panics, protesting, "No, stop it...!!" and tries to push him away, but he refuses to stop. Overwhelmed by his intense persistence, the mother finds herself sinking deeper into confusion and desire.