Yoshiko gave birth to Yuuki when she was a college student. The father wanted her to have an abortion, but Yoshiko chose the path of being a single mother. Even though they were a single-parent household, she worked tirelessly so that no one would pity them, and Yuuki never made unreasonable demands. However, working late into the night and having almost no days off, loneliness built up within the mother. Even when they went on a hot spring trip to use up her paid leave, Yoshiko was only worried about work…
