Maiko, a mother who lives with her daughter and her husband who are worried about living alone. She had a good relationship ostensibly and she had no problems, but her frustration piled her up and she indulged in masturbation night after night. Then her son-in-law, Hikaru, is secretly peeking into her foolery ... Maiko, who he knew was a big dick, couldn't control her overflowing lust, and she seduced him obscenely every time. Her son-in-law, who inflates a big cock to her repeated foolery of her mother-in-law, can't stand it at last ...