Worried about his aging father, the couple Mahi and their father-in-law Toru decided to live together. The father-in-law couldn't stop thinking about his beautiful daughter-in-law, Kaoru. He would peek at her while she was taking a bath every day.... One day, he saw Kaoru having sex with his son, and after they finished, he saw Kaoru masturbating next to his sleeping son... Feeling that Kaoru was not satisfied with the sex with his son, Toru went to Kaoru the next day...
