The elegant and refined Kasumi, a woman in her fifties, is a total nymphomaniac despite her appearance. This mother, who engages in lewd acts with her only son Koji every night, can't wait for him to return home and indulges in intense masturbation. One night, Koji returns home with his drunken friend Takashi. Witnessing the mother and son engaging in their lewd activities, Takashi becomes aroused and decides to confess his feelings. Upon his return, the lust-crazed fifty-year-old mother boldly spreads her ripe pussy and seduces Takashi.
