The hero of the story is Kai Ichinose, a talented piano boy. When he was a child, Kai happened to play a special abandoned piano in the forest. No one except Kai could play this piano. Through this special piano, Kai developed his piano talent. His playing power is stronger than that of ordinary people, and he can even break the strings. Because of the piano, Kai met Sosuke Ajino, a former talented pianist who ended his playing career due to a car accident. Sosuke Ajino also became Kai's piano master. At the same time, Kai also met his lifelong friend and rival Shuhei Amamiya.