Shota Kamine, a Meien High School student, has the power to "see" people's emotions as anthropomorphic hearts. What he had always seen were sad, wounded and broken hearts. Whenever he tried to change the condition of people's hearts he failed. It depressed him and made him lose hope. What good was his ability to see hearts but not the power to help them? By chance Kamine gets invited by Tokisaka Hibiki to the auditorium to watch him perform the saxophone. Hibiki's playing was so moving that it affected Kamine's own heart.
While Tokisaka Hibiki was performing, Shouta Kamine noticed that he had cure those audiences' heart, like giving them a punch. After the performance, Shota Kamine asked him how did he did it. But, what Tokisaka Hibiki answered was that he couldn't cure one people heart. Tokisaka Hibiki took him to a hospital, where his neighbour and childhood friend, Takizawa Momoko. Shota Kamine was shocked as what he saw in Momoko's heart was in utter despair.
The next day, Hibiki took Kamine to the hospital again to use his saxophone to reach Momoko. Kamine conducted him all along. When Hibiki and Kamine both stoped, Momoko cried. When they left the hospital, Hibiki invited him to be a conductor in the concert band. But did he agree to?