Nobuko has been living with her daughter and her husband for several years after her beloved husband passed away. The relationship seems to be going well, but then Yukio, the daughter-in-law, accidentally sees Nobuko masturbating. From that day on, Yukio cannot forget Nobuko's beautiful and bewitching lasciviousness... On a holiday when they happen to be alone together, he sees Nobuko's backside and has a flashback to that day's lasciviousness. Yukio knows it's wrong, but he can no longer contain his excitement, and he throws reason to the wind...
