The Age of Shadows
밀정 (original)
Set in the late 1920s, The Age of Shadows follows the cat-and-mouse game that unfolds between a group of resistance fighters trying to bring in explosives from Shanghai to destroy key Japanese facilities in Seoul, and Japanese agents trying to stop them. A talented Korean-born Japanese police officer, who was previously in the independence movement himself, is thrown into a dilemma between the demands of his reality and the instinct to support a greater cause.
Starring Song Kang-ho, Gong Yoo, Han Ji-min, Shingo Tsurumi, Um Tae-goo, Shin Sung-rok, Lee Byung-hun, Park Hee-soon, Heo Sung-tae, Kim Dong-young
It's a action & adventure and drama movie, and has a rating of 7.1 out of 10 from Imdb which is usually fine for this kind of movie.
Watch it here
Not found streaming from United States.