Hello everyone, may I ask you a little question? 
So I pretty new in world of dramas, but, obviously, I fell in love with it. So I'm looking for something: 
- after 2014 
 - non comedy, supernatural and historical
 - real matters involved, serious maybe? 
- bittersweet ending (I know it's hard since lots of dramas have to have lovely ending) 
- maybe a little romance (but of course in intelligent way) 
Welcome to MDL :)

Some you should really watch:
Tunnel
Stranger
Defendant
Bad Guys
Duel
Remember – War of the Son
A Beautiful Mind
The Good Wife
Healer
Love Me If You Dare
Aishite tatte, Himitsu wa Aru

Woman of Dignity
Marriage Contract
Angry Mom
Circle
Night Light
On The Way To The Airport
Plus Nine Boys (2014)
Queen of Mystery
+1 The Guardians
Valid Love (2014)
Lookout/The Guardians
I Remember You
Save Me (currently airing; it's amazing!)
Remember: War of the Son
Duel
Voice
Defendant
Cruel City (2013, but the cinematography is pretty good)
Uncontrollably Fond
Moonlovers: Scarlet Heart (historical, but it's really good)
stranger
defendant
bad guys
Missing Noir M

among which stranger would be the best, missing noir has the bittersweet ending kinda.