One day, Yuzuru, who lives alone, meets Tsumugi, a married woman stuck in his neighborhood. When her bicycle breaks down, Yuzuru saves her and becomes friends with her... As the relationship progresses, the relationship between the two deepens. Yuzuru gave Tsumugi a duplicate key, and when her husband left for work, Tsumugi started heading to Yuzuru's house with her shopping bag in hand. Then, as if to relieve the loneliness of the couple's misunderstanding, they begin to spend a lot of time together in Yuzuru's room...