Fuyuna Asakura

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.

Ayame finds herself often in a numb state. She suffers from a disease which causes her to feel sleepy regardless of the time. Ayame also has a reoccurring daydream. One day, Ayame daydreams that her younger sister Hiiragi dies. This time around she'll have to fight her own dreams.