Housewife Nao spends her days caring for her husband and father-in-law. Recently, her father-in-law's dementia has worsened, causing him to increasingly recall his deceased wife. To comfort him, Nao begins impersonating the late wife, devoting herself wholeheartedly to his care. But her kindness leads them down a dangerous path. One day, the father-in-law begins intensely desiring Nao's body. Understanding his emotions and entangled with her own desires, Nao gives in and becomes intimate with him. The loneliness of feeling abandoned by her husband deepens their bond, gradually escalating into passionate, creampie-filled sex. Their bodies entwine like a married couple, radiating an eerie, inexplicable warmth...