Hiroto Suwa, now 26, along with his wife Naho and their former high school friends—Takako Chino, Azusa Murasaka, and Saku Hagita—gather at Mt. Koubou to admire the cherry blossoms. As they watch the sun go down, they reflect on their friend Kakeru Naruse, who passed away a decade earlier. In their grief, they choose to visit Kakeru’s childhood home, where his grandmother reveals the truth behind his death.