Aya married a man with a child a year ago. By the time he got used to his new family and began to build a happy family life, Aya was gradually appearing in front of his family in a defenseless manner. For her adolescent son, the appearance of Aya, whose plump chest was exposed, was too exciting. One day, when she had a frustrated feeling, her husband's business trip caused Aya and her son to spend the night alone.