In the middle of a forest rests an abandoned piano. If one were to walk by, they may hear music coming from it, and sitting at the chair is a young boy: Kai Ichinose. He lives with his young, single mother—who works as a prostitute—and he is somewhat of a troublemaker at school when it comes to defending transfer student Shuuhei Amamiya from class bullies.

Shuuhei comes from a family of distinguished pianists, so he is expected to follow in their footsteps. He practices rigorously every day to live up to his parents' expectations. Meanwhile, Kai—with help from his teacher, a former pianist legend—wants to not only reach Shuuhei's level of success, but also wants to become the best pianist from Japan. This rivalry between the two friends will not only raise their talents to new levels, but it will also inspire other rising pianists from all over the world.