recommendation

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) 

The Guardians

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)