Mariko, who is frustrated due to lack of sex with her husband, secretly consoles herself during her troubled days. One day, she finds out that her son-in-law, Shinji, who lives with her, secretly masturbates for the same reason... Mariko, who was captivated by the sub-standard big dick she happened to see, told herself that she was doing it to vent on her daughter's behalf, and continued to secretly seduce him whenever she had a chance, day or night. And Shinji can't resist the lustful charm exuding from his stepmother, and continues to be played with his cock over and over again...
