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 South Korean box office.
Lee Kang-hee, the chief editor at an influential conservative newspaper, raises congressman Jang Pil-woo to the position of leading presidential candidate using the power of the press; behind this is his secret deal with the owner of the paper's biggest sponsor, Mirae motors.
Ahn Sang-goo, a mobster boss who supported Lee and Jang behind the scenes by doing their dirty work, gets caught pocketing a copy of the record of the sponsor's slush fund. Lee and Jang believe that Ahn's ambitions have outweighed his usefulness and decide he is a loose end to be tied up, resulting in his hand being severed by Managing director Jo, Jang's assistant and enforcer, as punishment. After recovering, he attempts to go public and expose the slush fund, but due to being known as a gangster, his accusations are easily discredited by the media through the machinations of Lee and Jang. Though Ahn survived his ordeal, he no longer has any ability to convince the public of the truth. However, he secretly maintains possession of his copy of the slush fund record.
Woo Jang-hoon is an ambitious up and coming prosecutor who, due to his humble socio-economic background, lacks the network of connections among the rich and powerful that is needed to advance his career. He starts to investigate the relationship between Jang and Mirae motors, believing that it's his best and only chance to make it to the top. While getting down to the brass tacks of the case, Woo is repeatedly obstructed by the influence of Lee and Jang, who bribe, threaten, and coerce any and all key witnesses. Woo then meets Ahn, who has been methodically planning his revenge.
The war between the ones blinded with power, the one hell-bent on vengeance, and the one eager for success begins, as prosecutor Woo, with the help of Ahn, becomes an "inside man" to expose the corruption of Lee and Jang to the people.
On its first four days at the South Korean box office, the film grossed . Inside Men drew more than 2 million viewers in just six days, a record for an R-rated film; it has also set the record for the most-viewed R-rated movie in a single dayâÂÂ489,503 viewers.