U (유) is a South Korean singer and rapper under Pacemaker Entertainment. He is a former member of the boy groups VERMUDA and 100%.
On September 14, 2012, the first teaser of 100% was released for their then upcoming single album We, 100%. He officially debuted with the group on September 18, 2012 with the release of the single album.
On September 12, 2016, TOP Media announced the departure of Changbum from 100% after discussions.