Super Junior's first major tour

Super Junior's first major tour, THE 1ST ASIA TOUR CONCERT ALBUM SUPER SHOW, started on February 22 to February 24 in Seoul. The tour covered nine different cities, including Bangkok, Shanghai, Beijing, Taipei, Kuala Lumpur, Tokyo, and Hong Kong.
Super Junior-Happy made an unofficial debut performance on May 3, 2008 at the Power Concert although they had not formally introduced themselves as the subgroup at the time. On May 30, SM Entertainment released the official announcement of the subgroup through news agency Newsen. The subgroup's first mini-album, COOKING? COOKING!, was released on June 5, 2008. The music video for their title track was released on that same day.
On June 7, Super Junior-Happy debuted performing their first single at the 2008 Dream Concert. On the day before their debut, the subgroup held their first sign fan meeting to celebrate the success of the sales of COOKING? COOKING!. On the morning of June 6, over thousands of fans lined up for tickets to the fan meet, overcrowding the streets. Close to 10,000 copies were sold by the first week of release. According to the Music Industry Association of Korea, the mini-album sold 20,978 by the end of June and was ranked fifth in the monthly charts.
On July, the group announced that Super Junior will end subgroup activities at the end of the year and will come together to prepare for their third studio album, which was slated to release in 2009. Super Junior's held their Japan fanmeeting in the Nippon Budokan in Tokyo as a celebration for the grand opening of their official Japanese homepage that was opened on April 1, 2008.
Their first Japanese single "U/TWINS", was released in Japan on July 9, 2008. The single peaked at #4 on Japan's Oricon Daily Chart in its first day of release. The single broke a new record for being the first single from a Korean group to debut in top 10 on Japan's Oricon Weekly charts.
On August 2, Super Junior expanded their routes to Genting Highlands, Malaysia, being one of the top guest performers at the MTV Asia Awards 2008. They were the third SM artist to win "Favorite Artist Korea" at the MTV Asia Awards after Kangta and BoA.
On August 3, Super Junior-Happy started the promotions of their second lead track, "Pajama Party". The music video was released on August 4, 2008. "Pajama Party" promotions only lasted a month, and promotions for the mini-album officially ended on September 7, 2008.
On November 5, Super Junior-T debuted in Japan with the release of "ROCK&GO", a Japanese version of their debut Korean single. It was also a collaboration effort with Japanese comedic duo Moeyan.