Super Junior-M, Super Junior's Mandopop subgroup comprising members Hankyung, Siwon, Donghae, Kyuhyun, Ryeowook, and Super Junior-M members Henry and Zhou Mi, was formed in April 2008. Although the creation of the subgroup initially created a strife between the group's fans and their management, Super Junior-M went on to become Super Junior's most successful subgroup, selling out two concerts in Hong Kong, topping weekly ratings with their appearance on Chinese variety programs, and was the idol group with the most endorsement contracts in China. They won numerous awards at Chinese music festivals, and achieved critical acclaim after the release of their single "Super Girl" from their second record Super Girl, which garnered them a nomination for Best Vocal Group at the 21st Golden Melody Awards. A fourth Super Junior subgroup was created soon after Super Junior-M's debut. With five members from Super Junior-T and Yesung, they formed the subgroup Super Junior-H, releasing their first extended play (EP) Cooking? Cooking! on June 5, 2008. In November 2008, Super Junior-T made a debut in Japan, collaborating with Japanese comedy duo Moeyan. Their single "ROCK&GO", the Japanese-language version of "Rokuko", debuted at number 19 on the Oricon Daily Charts and ascended to number 2 three days later.
Super Junior's first Asia-wide concert tour, Super Show, started on February 22, 2008, in Seoul. The group held a successful two-day fan meeting in Japan at the Nippon Budokan in Tokyo, selling out 12,000 tickets in several days. The group released a compiled single "U/Twins", which includes the Japanese version of "U" in the limited release version, to complement the event. The single peaked at number four on Japan's Oricon Daily Chart on its first day of release, and dropped down four places on its second. The single broke a new record for being the first Korean single to have made within top 10 on Japan's Oricon Weekly Chart.
The group released their third studio album Sorry, Sorry on March 12, 2009. It was their first album to debut at number one on the Hanteo Charts, selling over 29,000 copies the first day. After only a month of release, the album became South Korea's best-selling album of 2009, and ultimately sold over 250,000 copies in South Korea. It became the best-selling K-pop album in Taiwan, Thailand, China, and the Philippines, in which the latter credited the album to be the first K-pop album to reach number one in music charts from the country. The album's title single "Sorry, Sorry" became an instant hit, collecting a total of ten number-one awards for ten consecutive weeks in Korea, and stayed as number one for a record-breaking 37 weeks in Taiwan's K-pop singles chart. "Sorry, Sorry" achieved national and international success, and has since been the group's best-selling single in South Korea. Sorry, Sorry won several accolades at the 24th Golden Disk Awards, including the Disk Daesang (Record of the Year).
After the success of Sorry, Sorry, Super Junior commenced their second Asia-wide concert tour Super Show 2, on July 17, 2009 in Seoul.
