Kousei Arima, known as the 'Human Metronome' for his flawless piano performances, loses his musical prowess after his mother's death. Retreating from the limelight, he lives quietly with his childhood friends, unable to play. His world shifts when he meets Kaori Miyazono, a free-spirited violinist who challenges his rigid approach to music. As their bond deepens, Kousei's life transforms with newfound friendships, love, and the power of Kaori's influence, reigniting his passion for music.