Yuriko's nightly married life with her husband had always been simple and bland. They would undress the same way every time, and that was it. Unable to muster the courage to seek new excitement, she ended up drowning in her own fantasies, passing the days in solitude. Then one night, after finishing her usual masturbation session in the bathroom, she returned to the living room and saw her son sleeping with a hard bulge in his crotch. It was a shocking sight.