Riko is a housewife who lives with her husband and daughter. Although he lived a happy life without any inconvenience, trivial quarrels with his husband who became a remote worker began to increase. One day, Riko witnesses the splendid Ichimotsu of her son-in-law, Masaki, in the bathroom. Riko's instinct is shaken by the exciting sight she saw for the first time in a long time ... And Masaki begins to try a relentless approach to Riko as if she had calculated it! "Your mother-in-law is frustrated ... Let's become an animal with me!" Riko was rubbed by Masaki with her abundant big tits and was rubbed into the whirlpool of affair.