Kim is also prominent as a regular cast member in variety shows Master in the House, DoReMi Market, The Return of Superman, and Strong Heart.

And later Kim began to practice Judo professionally at Yong-In University, which led him to reignite his MMA career.

As one of the largest members of the gym, Kim became a regular sparring partner of middleweight Yushin Okami.

He mentioned during Law of the Jungle that before spending four months in Auckland, New Zealand working in 3 concurrent part-time roles (kitchenhand and sashimi chef/poissonnier, bricklayer and construction labourer).

Kim was also featured along with fellow UFC fighter Yoshihiro Akiyama in the Korean boy band MYNAME's drama music video for their single "Baby I'm Sorry".

In September, 2018, he announced his marriage to Song Ha-ryul in various variety shows,[9] then revealed her pregnancy on the February 14, 2019, episode of Amazing Saturday.

Kim's performances attracted the attention of World Extreme Cagefighting (WEC) talent scouts, who offered him a contract.

One week before the event, a prime time, hour-long special about Kim was aired on Korean television.

[12] He made his second octagon appearance at UFC 88, capturing a split decision over The Ultimate Fighter 7 alumnus Matt Brown.

During this fight, Kim's conditioning was very poor due to jet lag, and visa problems prevented him from bringing a coach.

[13] Kim returned to the octagon in Las Vegas, Nevada, on January 31, 2009, as he faced off against fellow judo practitioner Karo Parisyan at UFC 94.

Grant at UFC 100, winning by a unanimous decision, threatening with a guillotine choke midway through the second round.

He was scheduled to fight Dan Hardy on November 14, 2009, at UFC 105, but was forced to withdraw due to ligament injuries of his right knee while sparring with Kazuhiro Nakamura[22] and was subsequently replaced on the card by Mike Swick.

Kim was then expected to face fellow undefeated fighter John Hathaway at UFC 120,[25] though he was later replaced by Mike Pyle due to elbow ligament injury from training.

[26] Kim defeated The Ultimate Fighter season 5 winner, Nate Diaz on January 1, 2011, at UFC 125 via unanimous decision.

After the fight Kim called out current UFC welterweight champion, Georges St-Pierre, whom he considers a hero and role model to himself as a mixed martial artist.

[28] Kim lost to Carlos Condit on July 2, 2011, at UFC 132 via first-round KO due to a flying knee.

[32] The bout was stopped in forty-seven seconds in the first round by referee Mario Yamasaki, after Maia took Kim down and ended up in the mounted position.

Many observers, including the UFC commentator Joe Rogan, thought that Kim had broken a rib during the bout, but it was later revealed that he suffered a major muscle spasm while defending Maia's takedown attempts.

[50] However, on November 14, it was announced that Masvidal would instead face Benson Henderson at the event after his scheduled opponent Thiago Alves pulled out of their fight.