Yuriko, who was left behind by her husband, decides to live with her daughter and son-in-law. Yuriko, who couldn't sleep late at night, noticed the sounds leaking from her daughter and son-in-law's bedroom and secretly peeked in to find them in the middle of the act. And a few days later, while secretly peeking at her daughter and son-in-law's act again, Yuriko indulged in masturbation. A few days later, while her daughter was traveling, Yuriko checked on her son-in-law and found him handling his crotch alone. Yuriko entered the son-in-law's room pretending it was an accident. She smiled gently at the embarrassed son-in-law and said, "It's okay..."