Masao has a very high sexual desire, while his wife is completely opposite. She always tries to avoid intimacy whenever Masao desires it. This time, Miho came to visit her daughter's house for a while. Mesmerized by the beauty of her mother-in-law, that night, while his mother-in-law was taking a bath, Masao secretly took Miho's underwear to masturbate. Unfortunately, Miho caught him in the act, and Masao had to tell her the truth about the intimate relationship between the couple. Knowing this was her daughter's fault, Miho wanted to make it up to Masao by giving him oral sex. However, Masao's sexual desire not only did not decrease but increased even more. He wanted to have sex! With no other choice, Miho had to please her son-in-law. But since her husband had passed away a long time ago, Masao's strong performance made Miho enjoy pleasure that she had long forgotten. From then on, Miho secretly let Masao have sex whenever there was an opportunity. She even thought about staying here to satisfy her son-in-law's sexual desires every day...