Twenty-six-year-old Hiroto Suwa; his wife, Naho; and their old high school classmates—Takako Chino, Azusa Murasaka, and Saku Hagita—visit Mt. Koubou to view the cherry blossoms together. While watching the setting…

One day, Naho Takamiya receives a letter written to herself from ten years in the future. As Naho reads on, the letter recites the exact events of the day, including…