Due to her husband's work transfer, Momoko Kikuichi lives alone, burdened by loneliness. Her daughter and son-in-law, Kimihiko, temporarily return home. Initially hesitant and reserved, Kimihiko gradually grows closer to Momoko. One day, when Kimihiko suddenly falls ill, Momoko tenderly nurses him back to health. Touched by her kindness, he begins to see her not just as family, but as a woman. Their relationship soon crosses forbidden boundaries. Living under the same roof, what began with guilt and taboo slowly transforms into pleasure. As familial bonds intertwine with illicit desire, a new and forbidden passion blooms between Momoko and Kimihiko.