Three dramas I'm currently watching might fit your criteria:
- School 2013: I've watched 11 Epsiodes so far. The drama portrais different aspects of difficulties teenager have to face while growing up. Plus it shows how beautiful friendships can be. I personally love the drama very much.
- Misaeng (aka Incomplete Life): Very realistic view on daily life in office to the point, where it can get quite frustrating. Nevertheless the show also hast its' uplifting moment.
-'Good doctor' is about a doctor with savant syndrome and a developmental disability, which is why his mental age is the one of a 10 year old. Only watched 2 episodes so far, but I can already tell, that the drama will be one of my favorites. The main character -although different from his colleagues- shows deep affection towards his patients. Love the show for its' heartbreaking but also heartwarming moments. I'm really glad, that I still have quite a few episodes left.
All shows mentioned above are realistic and feature great acting