Korea may not have a friendly neighborhood Spider-Man, but it does have secret neighborhood martial arts masters protecting people from the criminal world. But don't be embarrassed if you haven't heard about these special heroes, actors Kim Woo-bin and Kim Sung-kyun of Netflix's upcoming action film "Officer Black Belt" had no idea who they were either.

“I'm ashamed to admit that I didn't know who they were,” actor Kim Woo-bin said during a press conference for the film, held in Gwangjin District, eastern Seoul, on Tuesday.


“It was my first time coming across the job, though I think I've heard about probation officers in the news before. After meeting and speaking with the officers in person, I realized that I was unaware of the challenging and remarkable work they were doing, even though they've always been around us.”

The new action film, set for release on Sept. 13, centers on the journey of Jung-do, a talented martial artist who becomes a martial arts officer after teaming up with a probation officer to fight and prevent crime. The film follows the two, who monitor and track down criminals wearing electronic ankle bracelets to protect the neighborhood.

Martial arts officers and probation officers, jobs that may be unfamiliar to the public, are public servants under the Ministry of Justice. They work as a pair, monitoring the locations and movements of individuals wearing electronic ankle bracelets. They aim to prevent criminals from reoffending by operating a 24-hour surveillance system, which involves tracking criminals down and carrying out undercover operations.

Directed by Kim Joo-hwan, who was also behind several action pieces like action film “Midnight Runners” (2017) and Netflix action series “Bloodhounds” (2023), the film features actor Kim Woo-bin, who plays Jung-do, and Kim Sung-kyun, who plays probation officer Sun-min.

Though the jobs were unfamiliar to the actors, the director knew about the jobs for quite some time and revealed that his personal experience led him to delve deeper into the subject.

“While I was researching the jobs, a notice arrived at my home, indicating that someone wearing an electronic ankle bracelet was living in my neighborhood,” director Kim said. “[Such an experience] made me think about those people living near my home, which led me to delve even deeper into the topic.”

Actor Kim Woo-bin, who mainly overpowers his opponents physically in his role, made a few physical changes to more appropriately depict his character and background. He gained some weight and dyed his hair blonde, as he is portrayed as an ordinary person who naturally seeks fun while also having expertise in taekwondo, judo and kendo.

“I wanted to look more imposing and capable of overpowering my opponents, so I started gaining weight and ended up adding about eight kilograms (17.6 pounds),” Kim said. “I thought [Jung-do] would look better with some body fat and a fuller face rather than a sculpted, ripped physique, as he is a person who enjoys exercising, chases after fun and lives a happy life.”

For Kim Woo-bin, it seemed that the physical change was part of a bigger picture to thoroughly depict the growth of his character, saying, “I also wanted to show Jung-do’s transformation through him losing weight and changing his hair.”

In the film, Kim Woo-bin also shows a new type of action, which the director dubbed “ hangari [large clay fermentation pot] action.” It was the first time the director had tried such an action scene during his career.

“I think we might have created the world’s first action scene involving hangari,” the director said. “Although it looks simple, we carefully spent a lot of time determining the right material for the pots and the amount of gochujang [Korean chili paste] needed inside to avoid injury while capturing the right effect.”

Probation officer Sun-min is a “straight up good-natured person,” according to Kim Sung-kyun, who plays the role, adding that he also tried to capture the human side of his character’s job.

“I realized that they don’t just oversee and control individuals, but also act as an older brother, offering guidance and support when needed, and at times, take a firm stance in their duties as probation officers,” Kim said, admitting that he first had the impression of them being very rigid and intimidating.

The film may seem just like an entertaining, action-packed film, but the director hopes to deliver a deeper message.

“When preparing for this project, I started with the question of whether we are still capable of doing good in a world where compassion seems to be diminishing,” the director said. "I wanted to tell the viewers that people can still do good for others.”

“We put a lot of effort into delivering that message in an entertaining way, combining action, humor and thrills into a complete package. We hope you enjoy it this Chuseok.”

BY KIM JI-YE [kim.jiye@joongang.co.kr]