Hibiki Muroi

Yuri Kashiwaga was once known as a genius pianist. One day, she returns to her hometown in Goto Islands from Tokyo. There, she begins to work as a temporary teacher at a middle school and advisor for the school chorus. The chorus aims to take part at a competition. Yuri gives the members of the chorus members an assignment. She instructs them to write a letter with the title of “To myself 15 years later.” The 15-year-old boys and girls write about their secrets and worries.

Mirei Katagiri transforms her life with plastic surgery before starting college, gaining newfound admiration from her peers. However, her world is upended when her secret comes to light, coinciding with a reunion with her middle school classmate, Kei Sakaguchi.