Yurina, a married woman appointed as the new neighborhood association leader, eagerly begins her duties. However, she quickly discovers unaccounted expenses in past financial records. When she consults veteran member Tonegawa, he hides his knowledge of the discrepancy and sends in a young local man, Hyodo, to silence her. Unaware and naive, Yurina succumbs to his advances and gives in sexually despite being married. But this decision plunges her into deeper confusion and nightmare, and by the time she discovers his true identity, it is already too late.