Awl (2015)

The Running Mates: Human Rights had a case about union labor members and their struggles that was what Awl was about..

If you like the way Stranger is filmed, check out Awl. It's produced by the same company & I suspect it shares the same filming crew (at least to some extent). Both have very elegant, muted colour palette consistent through a whole runtime (greener in Awl, blue to light warm brown in Stranger). Music is limited mostly to background sounds and instrumentals and it's sparsely used, OSTs come mostly in ending credits, like a MV's teaser. Flashbacks are used for the sake of the storytelling, not filling the empty spaces to meet the time limit. Both are of excellent quality.
One of the main characters in both isn't very expressive and doesn't socialise much (in Stranger he's nearly emotionless due to a brain damage, in Awl it's just a way he is: gentle and rigid).
The topics are different, but hitting similar tones and both approach them with similar attitude: showing some kind of a corruption in a broad context, as a systematic, social failure based on relationships between humans. Stranger is sexier and wittier as it takes place between Prosecutor Office and Police and involves high officials and men in power, whereas Awl's more revolting (it showcases a conflict between a labour union and a mart's foreign executives), yet both have similar down-to-earth setup and problems are solved in a realistic pace.

Both works are based on the same real life event that took place in South Korea in 2007 where temporary cashiers at a mart were fired and decided to strike.

Based off of webcomics, these two workplace dramas feature MCs that do their best to survive in a harsh reality—Miseang focuses on an entry-level grunt in a trading company and Awl a manager who forms a union in a supermarket. No makjang antics, just great acting and unexpectedly gripping plotlines.