Through Netflix action comedy “Officer Black Belt,” Kim Woo-bin said he became appreciative of the “unseen” heroes ensuring people’s safety every day.

In this coming-of-age film, Kim plays Jung-do, a young man gradually exposed to the world of martial arts officers and probation officers. He accidently bumps into a probation officer chasing after a criminal wearing an ankle monitor on the run.

Before shooting began, Kim said he had no idea what the job was about. But he felt a strong attraction after reading the scenario.

“As it had been a while since I last starred in a comedy, reading an action comedy scenario felt new to me, but I could sense that the director wanted to let people know more about this very little-known job. I could genuinely feel his intention. So I decided to join his effort to create a fun project to help raise people’s awareness of martial arts officers,” Kim told reporters during an interview in Seoul on Thursday.

The movie topped Netflix's weekly non-English movies chart almost immediately after its Sept. 13 release, proving that viewers not just in Korea but around the world enjoyed exploring the world of probation and martial arts officers.

Kim expressed hopes that audiences would feel the same as he did after shooting the project.

“There are so many ‘unseen’ heroes in our society who work day and night to protect people and make sure they feel safe in everyday life. I just hope the audience also appreciates these heroes after watching this movie,” Kim said.

The movie has received favorable responses for mixing a weighty message with witty comedy and thrilling action sequences.

Kim said he trained for the action sequences involving sports such as taekwondo, kendo and judo.

“(In the movie,) Jung-do plays three different sports, so the action shows a lot of sports-inspired steps, and uses props like a mannequin leg in place of a stick in a kendo fight,” said Kim.

To show action choreography that included delightful, rhythmic body movements, Kim said he worked with an action choreography director for more than three hours a day starting three months before shooting.

“I almost felt like a professional sports trainee,” Kim said, laughing.

“Officer Black Belt” is available on Netflix.