Two years after losing her husband in an accident, widow Yuu lives with her stepson, Shinkuro. After her husband's death, Shinkuro dropped out of university, refused to work, and became a recluse. Though Yuu continues to care for him, her devotion goes beyond mere duty. Even while her husband was alive, a special bond had begun to grow between her and Shinkuro. After his passing, Yuu realized her feelings for Shinkuro remained unchanged. Wanting to share this secret desire, she decides to invite him on a private hot spring getaway one winter.