In March 2006, SM Entertainment began to recruit new members for the next Super Junior generation. However, this was met with fans' objections and strong opposition to the rotational style (much like popular rotational groups in Japan's pop music industry) that the group intended to be. Thus, plans changed and the company declared a halt in forming future Super Junior generations. Following the addition of thirteenth member Kyuhyun, the group dropped the suffix "05" and officially named as Super Junior. The re-polished group's first CD single "U" was released on June 7, 2006, which was their most successful single until the release of "Sorry, Sorry" in March 2009. In February 2007, Leeteuk was placed in the trot-singing subunit, Super Junior-T. The subunit debuted with the single "Rokuko", which quickly reached number one in weekly music chart and held the spot for two consecutive weeks. A year later, Leeteuk became a member of Super Junior-H. Besides music, he also participated in Super Junior-centric television show such as Mystery 6 and Full House. He also made his first film appearance with Super Junior members in "Attack on the Pin-Up Boys" in 2007, taking the role of the school panda mascot.