Inside Men is a 2015 South Korean political action thriller film written and directed by Woo Min-ho based on Yoon Tae-ho's webtoon The Insiders that dissects the corruption within Korean society. Starring Lee Byung-hun, Cho Seung-woo and Baek Yoon-sik, it began filming in July 2014 and was released in theaters on November 19, 2015. Inside Men and the director's cut Inside Men: The Original have sold a total of 9.1 million admissions at the box office, thus becoming the top grossing R-rated movie of all-time at the Korean Box office.

Lee Byung-hun is a South Korean actor. He has received acclaim for his work in a wide range of genres, most notably Joint Security Area (2000); A Bittersweet Life (2005); The Good, the Bad, the Weird (2008); I Saw the Devil (2010); Masquerade (2012); and the television series Iris (2009) and Mr. Sunshine (2018). His critically acclaimed film Inside Men (2015) won him the Best Actor prize at the three most prestigious South Korean award ceremonies: 52nd Baeksang Arts Awards, 37th Blue Dragon Film Awards and 53rd Grand Bell Awards. Lee has seven films—Joint Security Area, The Good, the Bad, the Weird, Masquerade, Inside Men, Master, Ashfall and The Man Standing Next—on the list of the highest-grossing films in South Korea. Lee was Gallup Korea's Actor of the Year in the Film division in 2012 and in the Television division in 2018. In 2021, he appeared in a recurring role as the Front Man in the Netflix hit survival series Squid Game.