Absolutely a secret relationship. She took her son-in-law's heart and body. Even though she knows it's wrong, she can't stop. Tsubaki was drinking and listening to her son-in-law's complaints. Perhaps because he was also drinking, her son-in-law hugged Tsubaki. Tsubaki, who also felt lonely, gradually accepted him... One night, her son-in-law sneaks into Marika's bedroom. Marika, who knows the strained relationship between the daughter and her husband, accepted her son-in-law... Her son-in-law touched Natsuko's body and sought forbidden pleasure. Natsuko, even though she knew it was wrong, thought that she wouldn't have to feel lonely... In the past, only the missionary position was allowed for marital relations. For Aya, who only knew that, the daughter and her husband's sexual activity was shocking...