After separating from her husband, Toko raised Yuki alone. Wanting to spare him any hardship, she worked tirelessly, even continuing to earn money desperately to cover his tuition after he entered college. When Yuki finally started his career, Toko felt a sense of emptiness now that her parenting duties had eased. At that time, Yuki invited her on a hot spring trip, and the two set off together for a private graduation journey.