The year of 2012, late autumn. Tanaka Masashi, an architect, and Tanaka Misaki, a beautician, are in their third year of marriage. Masashi is invited with his wife on a friendship trip to an onsen by Aida, an executive director of the construction company, a frequent business partner of Masashi’s firm.
Laying in the open-air bath with Misaki, Masashi starts recalling the beginning of their love.