A mother, Erica, and a son, Satoshi, who divorced five years ago and became a single-mother family. The two will live in the countryside of Erica, but Satoshi, who has a shy personality, cannot easily make friends. Such Satoshi is the only one who can relax. It was my mother’s ass. Also, Erica begins to notice that her son, who touches her ass while doing household chores and sleeping, is adorable and gradually becoming happy.