The character is crafted very emotionally - he is sensitive, mostly mute, falls in love over the course of the movie, and is physically impacted with tinnitus, which he gained from a car accident involving his parents as a young boy.
His connection to music is prominent in the movie, with scenes timed perfectly to the backing track, or him deciding a song that reflects his mood.
If you are 15+, the movie is definitely worth a watch.
