The Sugiyama household has been stuck in a sexless marriage for over a year due to her husband Shigeru's involvement in managing rental properties. His wife, Ayumi, frustrated by his inability to satisfy her, secretly indulges in masturbation using a borrowed sex toy. One day, their neighbor Osawa comes by to deliver a community notice and accidentally catches Ayumi in the middle of pleasuring herself. Shocked to see such a refined and serious woman engaged in such an act, Osawa becomes overwhelmed with excitement and suddenly forces himself on her. As their bodies entwine, Ayumi feels a cock inside her for the first time in ages, awakening long-suppressed desires. In that moment, her true nature resurfaces, setting the stage for an intense new chapter.