One day, just before entering high school, Kindaichi Saki collides with a strange girl of the same year on the way to a piano lesson and grazes her hand, but the musical score she dropped is silently picked up and returned to her by the strange girl. Saki reunites with the impressive girl as a classmate and finds out that her name is Oikawa Kanon and that she is deaf. At school, Saki, who is lonely, tries to understand the sound of Kanon, who keeps a distance from her surroundings due to her disability, and her attitude gradually begins to change.