Pre-debut:
News about SM Entertainment's unprecedented plans of forming a large project group spread over the internet as early as 2004. In early 2005, SM Entertainment confirmed rumors and announced that a large twelve member all-boy group would debut near the end of the year, promoting the group to be "The Gateway to Stardom of Asia." For a while the group was known to be called O.V.E.R., an acronym for "Obey the Voice for Each Rhythm." Soon the group became known as Super Junior 05, the first generation of Super Junior.

Most members have been actors, MCs, models, or DJs prior to debut. Heechul, Siwon, and Kibum made their debuts in dramas and films. Leeteuk, Yesung, Kang-In, Shindong, Sungmin, and Eunhyuk made cameo television appearances and became active DJs or MCs after debut. Han Geng made his first media appearance as a model.

Super Junior 05 made their pre-debut appearance on the Korean channel, M.NET on September 11, 2005. At the showcase, Super Junior performed various styles of hip hop dancing. The group danced to B2K's "Take It To The Floor." Han Geng, Eunhyuk, and Donghae also performed a separate dance away from the group, dancing to Usher's "Caught Up." However, the performance did not air on television until May 16, 2006 as a segment in the Super Junior Show, the group's first television documentary.




2005–2006: The Super Junior project
Super Junior 05 made their debut television appearance as a group on SBS's Popular Songs on November 6, 2005 as a project group of twelve members. The group performed their first promotional single, "TWINS (Knock Out)." A digital single with "TWINS (Knock Out)", "You are the one", and three additional tracks were released online on November 8, 2005. A CD single was scheduled to be released on November but a more complete album, SuperJunior05 (TWINS), was released on December 7, 2005 instead. Their debut album sold 28,536 copies in the first month of release and debuted at #3 in the monthly chart of December 2005

An official fanclub was created for the group, E.L.F., an alphabetism derived from the phrase "Ever-lasting Friends."[3] The fans became known as as "elfs" (elves) in relation to the name of their official fanclub. Since Korean fans tend to support their idols with a certain balloon color, Super Junior 05's official color became pearl sapphire blue

To further publicize the company's newest project, Super Junior 05 collaborated with another boy band under the same label, TVXQ. They released a winter single titled "Show Me Your Love," a bubbly pop track for the Christmas season. During this time, the two groups were seen on the same shows together to promote their single. "Show Me Your Love" became the highest selling album of December 2005.

After "Show Me Your Love" performances and promotions were finished, Super Junior 05 moved onto their second single, "Miracle", a light bubblegum pop song. "Miracle" was the group's first single to peak at #1 on different music charts of South Korea as well as international charts from overseas countries, such as Thailand.[6] It was their last single to be promoted from SuperJunior05 (TWINS). As promotions for "Miracle" slowly came to an end, SM Entertainment decided replace some of the original members with new ones. Prior to Super Junior 05's debut, the group was intended a rotational group with new members replacing the old members who would leave the group. After Super Junior 05, Super Junior 06, the second generation, would debut, and the label had began to take actions to announce the new members. However, after the addition of a thirteenth member, the project group was changed to a permanent group and became known as just Super Junior, without the suffix "05".




2006–2007: "U" and breakthrough success
On May 23, 2006, SM Entertainment announced the addition of a new member, Kyuhyun, being the youngest member. The new thirteen member group released their new single, "U" online for free downlo