A girl watches her older sister sacrifice everything to raise her, then meets the ghost of the man who almost took that sister away. The movie doesn't punish anyone for it. The soundtrack becomes the only language for what these people can't say to each other, and by the end you understand why a song matters more than fixing the past.

Aoi has spent her teenage years feeling indebted to her older sister Akane, who gave up her plan to go to Tokyo with her boyfriend so she could care for Aoi after their parents died in an accident thirteen years ago. Now a second-year high school student and aspiring bassist in a mountain town, Aoi dreams of moving to Tokyo after graduation, and she is asked to play as a session musician for the enka singer Dankichi at a music festival. Around the same time, Shinnosuke, Akane's former boyfriend and now a struggling guitarist, comes back to town after years away. Then a boy named Shinno appears out of nowhere: he is Shinnosuke himself at eighteen, somehow carried from thirteen years in the past into the present. Aoi falls in love for the first time, and all four must face their feelings for one another and make choices that will shape their lives. The film is a drama blending music, romance and slice of life with a supernatural twist.