Kaoru, who divorced her husband, raised Yuki single-handedly. To avoid making him feel pitiful, she worked desperately and even sent him to university. Before she knew it, Yuki was of the age to graduate from college and had already secured a job at the city hall. While Kaoru felt relieved about raising a child, she lost her life goals and spent her days in emptiness. However, Yuki invited her on a hot spring trip saying, 'I want to comfort you for your hardships so far.' Thus, Kaoru and Yuki set off on their graduation trip for two.
