Mitsuko's daughter had moved out after getting married but was struggling with her job as a working mother, so she decided to live together again. Mitsuko was still single and couldn't help feeling lonely and sexually frustrated despite trying not to masturbate alone. One night, while walking past the living room, she caught her son-in-law masturbating upstairs. They both felt awkward about it and he explained that he hadn't been satisfying his wife lately during their intimate moments. Mitsuko couldn't help but stare at his large bulge and offered to help him...
