“Inside Men” is a scathing, absorbing work about the dirty tricks that manipulate public opinion and power in Korean society.

That might seem like nothing new. This year, the Korean box office has seen its fair share of movies discussing the corruption and collusion rampant in Korean society. 

But “Inside Men” is different because there is no good guy to root for. There is no justice-seeking lawyer as in “The Unfair” or righteous cop like in “Veteran.” Politician, prosecutor, columnist and mobster are all out for their own skins, gleefully flaunting their disregard for the rules and the idea of loyalty.

Based on the eponymous unfinished webtoon by Yoon Tae-ho, who also wrote “Moss” (which became a film in 2010) and “Misaeng” (adapted as a TV drama last year), the film takes the audience down a seemingly inescapable rabbit hole of immorality without cutting corners. The scenes are sexually and violently explicit, with secret meetings and decadent parties shrouded in sinister darkness by award-winning cinematographer Ko Rak-seon (“The Fatal Encounter,” “The Face Reader”). 

Luckily, director Woo Min-ho does a good job of taking Yoon’s unfinished series and pulling the characters together into a coherent storyline of betrayal and revenge. The fast-paced second half of the movie, decorated with a half-expected yet still surprising twist, plucks the audience out from their collective horror and brings them back into the comfort zone of a commercial thriller. 

“The film is very different from the cartoon,” Woo admitted at a press conference before the film’s release. “The original cartoon was very strong, and I tried to keep that strength in my plot.” 

“While the cartoon focused on the corrupt systems existing in Korea, the film focused on the intense competition between the characters themselves,” he said. 

And it is the characters that carry the movie, thanks to an expertly cast ensemble. Baek Yoon-sik plays kingmaker columnist Lee Gang-hui, who writes influential articles that sway public opinion to fit his needs. The prolific Lee Gyoung-young depicts politician Jang Pil-woo, a presidential favorite who widens his network with unsavory favors. 

Cho Seung-woo plays prosecutor Woo Jang-hun, who is determined to rise through the ranks despite his humble background, and Lee Byung-hun stars as Ahn Sang-gu, a thug fixer that does the bidding of powerful people with deep pockets. 

All four actors give stellar performances, but it is Lee Byung-hun who shines through -- so much that even the unforgiving Korean online crowd has praised his acting in early reviews despite recent personal scandals that had made him a public enemy. 

“I don’t like Lee as a person, but as an actor, he’s the best,” reads one comment. 

“In the end, Lee Byung-hun is Lee Byung-hun,” reads another.

From his carefully tailored looks to the way he eats ramen and the jokes he ad-libbed onscreen, Lee’s character leaves the strongest impression, while also providing comic relief. Speaking to reporters, Lee said that he put a lot of thought into creating the character.

“When I first got the script, Sang-gu was a very different person. He was more heavy and mobster-like than humorous. I thought the script was great, but I felt that the fast pace of the film didn’t give the audience any time to breathe,” he said. 

“I wanted to create a character and situations that provided those breaks, and the director gave me permission to take it in a more humorous direction.”

That humorous touch was the cherry on top for “Inside Men,” which successfully merged the deep, socially conscious message of cartoonist Yoon Tae-ho with the commercial movie style of Woo Min-ho. Even with all its darkness, “Inside Men” is an entertaining ride.

“Inside Men” opened Thursday.

By Won Ho-jung (hjwon@heraldcorp.com)