The Age of Shadows 2016 (South Korea)

The Age of Shadows 2016 (South Korea), also known as Miljung, Secret Agent, 密探 is South Korea drama premiere on Sep 7, 2016

Plot Synopsis by DramaWiki Staff ©

Lee Jung Chool once had connections to the Korean independence movement, but he now works as a police officer for the Japanese occupation's forces. He receives an order to take down the leaders of the Heroic Corps, an anti-Japanese resistance organization. But while Lee wants to keep his favorable position with the Japanese, he begins to question himself while chasing Kim Jan Ok, a key resistance fighter who used to be his classmate.
Then Lee meets art dealer Kim Woo Jin, whom he suspects is the regional leader of the group, and whose antique shop is a front for a scheme to smuggle explosives from Shanghai into Seoul. Both men are well aware of each other's true identities and intentions, but get closer to each other seeking out more information. Jung Che San, the leader of the Heroic Corps, wants to turn Lee—all while Lee is being hounded and watched by the suspicious officer Hashimoto. Conflicted over duty and loyalty, Lee knows he could become a traitor or ally to either side.
(Source: Written by MyDramaList)