Super Junior also known as simply SJ or SuJu, is a thirteen-member korean boy band formed by Sm Entertainment in 2005. The group initially debuted with twelve members on November 6, 2005 with the single, "TWINS (Knock Out!)". The original twelve members, from oldest to youngest, are Leetuk  (the leader), Heechul, Han Geng, Yesung, Kang-In, Shindong, Sungmin, Eunhyuk, Dongae, Siwon, Ryeowook and Kibum. The Chinese member, Han Geng, was chosen among the 3,000 applicants through auditions held in China by SM Entertainment in 2001.

Many of the members had already pursued an entertainment career before Super Junior's debut through acting, DJ-ing, and modeling. On May 23, 2006 SM Entertainment announced the addition of a new member, Kyuhyun, making them the thirteen-member group they are today.