Akari Niimura, a beautiful big-assed woman married to an older man and mother to his son. She hasn't had sex with her husband in over two years, leaving her with intense sexual frustration. To relieve the stress, she changes into sexy lingerie daily and indulges in masturbation. One day, her teenage son accidentally catches sight of her erotic act. This sensual scene becomes the moment that begins to unravel the family's bonds.