Yuki's mother, Chisato, became a single mother after her divorce 15 years ago. Chisato worked tirelessly to raise Yuki properly and saw him graduate from university and grow into an outstanding member of society. Yuki presented Chisato with a hot spring trip using his first salary. Although Chisato was genuinely happy that Yuki invited her on the trip, she also felt a sense of loneliness as if her role as a mother had come to an end…
