Kim Jun

Kim Joon made his entertainment debut with the boyband T-Max in 2007, as a rapper and a songwriter for the group. In 2009, Kim became popular after playing the role of F4 member "Song Woo-bin" in the hit Korean drama Boys Over Flowers. Together with his band, their song entitled "Paradise" was featured in the first edition of the Boys Over Flowers soundtrack. Other songs of T-Max that were featured in the subsequent editions of the Boys Over Flowers soundtrack were "Say Yes," "Wish You're My Love", "Fight The Bad Feeling," and "Bang Bang Boom".

As a solo artist, Kim also had a single in the soundtrack titled "To Empty Out," which featured Kim Jo-han. He also released another song he had written himself, "Jun Be O.K.," and Kim Hyun-joong made a cameo appearance in the music video of the song.

From April 2009 to December 2010, Kim was a cast member of Invincible Baseball Team, a variety-reality show that aired during Saturday Challenges; he was chosen as MVP for several weeks. In June 2009, he took part in another reality show Mnet Scandal, where a celebrity dates a non-celebrity for a week. In July 2009, he made his stage debut in the musical Youthful March (젊음의 행진), along with his T-Max co-member Park Yun-hwa. Kim tested positive for H1N1 in November 2009 and had to cancel a fan meeting event in the Philippines.

In March 2010, Kim starred in mobile drama alongside Nao Minamisawa titled Pygmalion's Love, a Korea-Japanese co-production that aired on Japanese mobile TV station BeeTV. In May 2010, T-Max returned to performing with "Don't Be Rude", the first single for their studio album Born to the Max (new members Park Han-bi and Joo Chan-yang replaced Park Yun-hwa after the latter's departure for mandatory military service). The second single was "Words That I Can Say", and Kim appeared alongside actors Oh Ji-ho and Yoon So-yi in the music video.

In March 2011, he starred in the police procedural Detectives in Trouble where he played a detective who specialized in cyber-investigations, but has trouble dealing with real-life cases because of his fear of corpses. He also began studying for a master's degree in Global Culture Content at the Hankuk University of Foreign Studies. A representative from his agency Planet05 commented, "Kim Joon has taken an interest in spreading Korean culture after he was able to meet with various international fans and after being named as an honorary ambassador of Global Tourism Etiquette. He wants to study the production of Hallyu culture content and its spread on a deeper level." On May 16, 2011, the T-Max members appeared on the game show 1 vs. 100 to raise funds for the establishment of an "invincible baseball" team; Kim advanced to the final 2, but did not win.