Yuri Kashiwaga was once called a genius pianist. One day, she returns to her hometown in Goto Islands from Tokyo. There, she starts to work as a short-term educator at a middle school and also expert for the school chorus. The carolers intends to participate at a competitors. Yuri provides the participants of the carolers participants a job. She advises them to create a letter with the title of "To myself 15 years later." The 15-year-old children and also ladies discuss their secrets and also concerns.