Keiko, being a single mother, didn't want her sons to feel pitiful and worked tirelessly. Before she knew it, Tatsuya was about to graduate from university and had already secured a job. With child-rearing seemingly over, Keiko felt an emptiness in her heart as if there were a hole. She felt like she had lost her life's purpose. It was then that Tatsuya invited her on a hot spring trip. 'I want to go on a graduation trip with the mother who got me into college.' Keiko and Tatsuya set off on their two-person graduation trip.
