Riko is a housewife who lives with her husband and her daughter and her husband. She lives a happy life without any inconveniences, but her husband started working remotely and they started having more and more petty arguments. One day, Riko witnesses her son-in-law Masaki's impressive penis in the bathroom. Riko's instincts are stirred by the stimulating sight she has not seen in a long time... And as if he had calculated this, Masaki begins to approach Riko relentlessly! "You're sexually frustrated, aren't you? Let's become animals together!" Riko's voluptuous, huge breasts are squeezed by Masaki, and she is drawn into the vortex of an affair...