Ten years ago, Rie Nishina lost her husband in a traffic accident and has since raised her son Kota alone. As Kota finally enters university and reaches adulthood, Rie begins to feel that her days as a mother are nearing an end—just as a remarriage proposal arises. She is drawn to a sincere, kind, and warm man named Okawa. Thinking of a future for both herself and Kota, she happily accepts his invitation for a hot spring trip and heads with him to Fukushima.