Riri is the daughter of the upper-class Nanatsumori family, and Takuto is a servant who has served them since childhood. Having known each other since they were young, Riri and Takuto have harbored feelings for one another, but kept them hidden due to their difference in social status. One day, Atsushi, the eldest son of the Nanatsumori family, receives military orders. Their father, Tokuji, an officer, is reluctant to let his eldest son go to a disadvantaged battlefield and comes up with a plan. He decides to bring Takuto into the Nanatsumori family as Riri's husband and send him to war as the second son. Feeling indebted to the Nanatsumori family, Takuto accepts, knowing there is no turning back. "I will let you spend one day together as husband and wife." Given just one day to be together, the two spent every moment loving each other until the time of parting.
