Tsubaki divorced her husband 14 years ago, and they split their two children: Tsubaki took the older son, and the husband took the younger son. Eventually, the children grew up; the eldest found a job and left home, and as if in exchange, the younger son came to live with Tsubaki. Perhaps because he was raised by a strict father, the son was independent and never showed any signs of acting spoiled or affectionate toward Tsubaki. Wanting him to feel even a little bit of her love, she invited him on a hot spring trip during a long holiday. However, that inn was a place with a fateful past for Tsubaki...