Rieko gave birth to Yuki when she was a university student. Her husband told her to have an abortion, but Rieko chose to be a single mother. Even though she was a single mother, she worked hard so that Yuki would not feel sorry for her, and Yuki responded by not being selfish. However, her mother worked late into the night and had almost no days off, which made her feel lonely. Even when they went on a hot spring trip to use up their paid leave, Rieko was only thinking about work...