 Not long after Choi's first television appearance, SM Entertainment released an announcement that he would debut as one of the twelve members in a boy band.A few months before the debut of Super Junior 05, Choi made his first media appearance with bandmate Han Geng as one of the runway models in a fashion show by Bum Suk.Choi debuted as part of 12-member rotational project group "Super Junior 05" on 6 November 2005 on SBS' music program "Popular Songs", performing their first single, "Twins (Knock Out)".