Aika lives in a two-family home with her daughter and her husband. She has recently noticed that her daughter and husband have not been getting along, so she sneaks in to check on them... She finds out that her daughter's husband, Shinji, has a dick that is too big for her to put in. Aika, who has not had sex with her husband for a long time, is fascinated by his huge cock and invites him in, making excuses to herself that it is for her frustrated son-in-law... Shinji, transfixed by her lewd body, can't help but devour him. As planned, Aika begins to enjoy his big dick day and night, hiding it from her daughter's eyes...