After divorcing her husband, Chieko raised Kouta on her own. To avoid making him feel pitiful for being from a single-parent household, she worked tirelessly, even after Kouta started college to pay for his tuition. Before she knew it, Kouta was about to graduate and had secured a job in the printing industry. With that, child-rearing seemed to be coming to an end. While she felt relieved, she also felt like her life's purpose had vanished, leaving a hollow feeling in her heart. When she was feeling lonely, Kouta invited her on a hot spring trip. 'You should take some time off work and relax,' he said. The two set off for the hot spring resort.
