Complex sentence: Kaori Miyazono is a pretty, free-spirited violinist whose playing style reflects her personality helps Kousei return to the music world and shows that it should be free and mold breaking unlike the structured and rigid style Kousei was used to.
Split into simpler sentences: Kaori Miyazono is a pretty, free-spirited violinist whose playing style reflects her personality. Kaori helps Kousei return to the music world and shows that it should be free and mold breaking unlike the structured and rigid style Kousei was used to.