Maki, the stepmother who is ignored by her husband, secretly masturbates to release her unfulfilled sexual desire. One day, her reclusive son, who always peeks at her through the crack in the door, becomes aroused by the sight of Maki's sexy back as she mops the floor in the living room with her buttocks completely exposed, and attacks her. Maki, who has completely forgotten about her reclusive stepson and believes she is alone, desperately tries to escape from him as he tries to pull down her skirt and underwear, but...