The autumn he was eleven, piano prodigy Kousei Arima suddenly found himself unable to play the piano after his mother's death. Ever since then, it's like he's been frozen in time. His childhood friend, Tsubaki Sawabe, watches over him with concern; one day, she invites him on a double date. Kousei's other childhood friend, Ryota Watari, is being introduced to a certain girl. Kousei reluctantly heads over to the rendezvous spot. There, he sees a girl playing a melodica. This girl, who allegedly has a crush on Watari, is Kaori Miyazono. And she turns out to be a violinist!