Since Masaaki was separated from his mother at a young age, he has lived with his father. In Masaaki's memory, his mother, Ema, was kind and beautiful. Time passed, and on Masaaki's 25th birthday, he received a letter from his mother. She wrote that she wanted to see him for the first time in 20 years. Masaaki gladly decided to meet her. The place for the reunion was a hot spring resort where the three of them had gone together long ago. At that time, Masaaki had not yet realized that his admiration for his mother had turned into romantic feelings...