"I have memories of the future." The unfamiliar girl who appeared before high school senior Mozumi Aruto said those words. Aruto, who had lost his childhood memories and the sound of the piano. Meanwhile, his younger brother Tokio was blessed with an innate talent for the instrument. "Why is it that I alone can’t hear the piano’s notes?" Haunted by this vague unease, Aruto couldn’t even confess his feelings to the classmate he adored. The final summer of high school. Guided by the girl who remembers the future, Aruto’s fate begins to shift dramatically. A bittersweet, fleeting summer love story.