Kasumi, who was living a happy married life, had a secret that she couldn't tell anyone. It was that she loved her stepchild more than her husband. At first, Kasumi and her son were nurturing love while her husband was away, but as her feelings for her husband faded, the act became more intense, and finally she could not stand it even by her husband and began to seek each other. . Kasumi, who does not want to destroy her happy family environment, holds her breath so that her husband does not find out, and enjoys pleasure, thrill, and climax.