With his wife visiting her parents, Atsushi struggles to manage household chores. Left alone in a messy home, his life takes an unexpected turn when his sister-in-law, Sora, arrives to help with the housework. Her sudden appearance brings him great relief, but Sora has her own hidden motives. Torn between the desire to support her sister's husband and fulfilling her own desires, she begins to act on conflicting emotions. Unaware of her intentions, Atsushi encounters Sora in the bathroom one evening... As daily tensions rise, their relationship takes a new and intimate turn.