Des：Souta, who married a daughter of the Ohara family as an adopted son-in-law, spends his days captivated by the plump breasts of his mother-in-law, Rio. One day, Souta decides to help Rio stretch. Sota, who has reached the limit of his patience as her huge breasts sway obscenely in front of his eyes, attacks Rio. Souta sees through Rios timid personality and pursues her even more. Their activities escalate, such as playing with Rios naked body covered in bubbles in the bathroom, and secretly having an affair while the family is together...