That day, the mysterious girl looked into my eyes and said, "I have memories of the future." Aruto Mozumi, a third-year high school student who lost the ability to hear piano sounds and lives in the shadow of his brother's talent, struggles to move forward. His relationship with the karate girl he has feelings for remains uncertain, while the guidance of a mysterious girl who claims to have memories of the future begins to dramatically change his destiny. Where will this love triangle, where the future and the past intertwine, lead? A bittersweet and fleeting summer of youth awaits.