Muto and Yuki, who work in the same workplace, are in an adulterous relationship, secretly seeking each other's bodies, out of sight of others. Both have families and cannot meet freely, but they share the same dream. "Just once, I want to forget everything and go on a trip to a hot spring just the two of us." To make this desire come true, they planned an adulterous trip in the guise of a business trip several months ago. On the day of the trip, the two meet at the station, change from their suits into casual clothes, board the Shinkansen in high spirits, and as soon as they arrive at the inn, they passionately kiss each other...