Rin raised Masaaki by himself and went on to college to welcome an adult. I felt that my child-rearing had settled down. At that time, I met a man because of my work. He was a man named Okawa who lives in Tochigi. Although there was a difference in age, Rin was attracted to Okawa, who was sincere and kind. The two met many times over a long distance. Rin, who began to think about remarriage with Okawa, invited Masaaki to go on a hot spring trip and headed to the mountains of Tochigi. On that trip, Rin learns about Masaaki's feelings ...