Kosei Arima was a piano prodigy until his cruel taskmaster of a mother died suddenly, changing his life forever. Driven by his pain to abandon piano, Kosei now lives in a monotonous, colorless world. Having resigned himself to a bland life, he is surprised when he meets Kaori Miyazono, a violinist with an unorthodox style. Can she teach Kosei not just how to play, but how to start living again?