Keiko, a voluptuous milf, lives her daily life unconcerned about her husband who returns home late every day. However, her son begins to suspect his father might be cheating and brings it up. Keiko brushes it off with a smile, yet she starts noticing her husband's prolonged absences. On top of her household duties, she's been indulging in masturbation during her private time, gradually exhausting her body. One day, completely worn out, she succumbs to drowsiness and loses consciousness. At that moment, her son suddenly returns home...