Tatsuki and Kyoko are step-parent and step-child. Tatsuki was raised as the child of Kyoko's late husband, who passed away five years ago, leaving the two to live together. Kyoko dotes on Tatsuki as if he were her own son, partly because of their close age difference, and Tatsuki deeply appreciates her kindness—so much that he gifts her a hot spring trip as a token of gratitude. However, Tatsuki harbors romantic feelings for Kyoko, and this getaway is driven not only by appreciation but also by his hidden desires.