コントラスト88

Pianist prodigies Shirou and Kurono are siblings who share a mutual rivalry, as well as a secret. When they play the piano, they can see the tune as an "apparition" in the form of a man. However, when Shirou becomes a high school student, he is no longer able to see it. He hides that fact from his sister and desperately continues practicing in order to catch up to her.