Chika moved in with her daughter and son-in-law. The three of them lived a lively life and it was fun every day, but every time she heard the sounds of the two young people having sex, she felt more and more frustrated. One day, while taking care of her stepson who had come home drunk after a drinking party, he pushed her down in a fit of impulse and they ended up having a physical relationship. Chika regretted it at first, but she couldn't forget the pleasure she felt... Later, when her stepson came to apologize, Chika...