 Ku released her first album "Breath" in 2009, an album of new-age music which included her composed song for her friend and singer, Gummy, entitled "Around the Alley".She then released her self composed and written digital single "Brown Hair" in 2010, with the music rearranged by bossa nova pianist Choi In-young.In 2012, Ku released "It's You" and its music video.