After losing her beloved husband a few years ago, Shinko now lives with her daughter and son-in-law. The harmonious relationship seemed to continue indefinitely, but Shinko's masturbation was accidentally seen by her son-in-law, Yukio. Since that day, Yukio couldn't forget Shinko's beautiful yet seductive lewdness... One day when they were alone on a holiday, the sight of Shinko's back triggered a flashback of that day's events. Despite knowing it was wrong, Yukio's excitement became uncontrollable, and he threw caution to the wind...
