I'm just curious to know...Is there a drama in which the main leads and the important side characters all die in the end? Kind of the thing we read in some books, the only survivor is the narrator who is not a part of the story at all,something like that.

I just watched A Love to Kill and it was so depressing that (not everyone died though) this thought occured to me.

Thanks in advance :)
Almost everyone died in these dramas...

Empress Ki
The Princess Wei Young
in the show (highlight from here to read further) sorry, i love you, mostly everyone dies. its a very good show requiring loads of tissues.
A lot of people died in Heartless city. One secondary-main (can't tell lol) is still alive though. 
Thanks, I'll check them out.
Scarlet Heart Ryeo lot's of characters died
movies:
- http://mydramalist.com/15552-love-lies - a sole survivor of a deadly love triangle.
- http://mydramalist.com/10980-coin-locker-girl

I understand you want something more specific than just main character(s) dying? Because there are many of those. Arang and the Magistrate - Master and Margarita. Ja Myung Go has main pair dying and almost everyone around them too (if it wasn't cut down, body count would be higher). Linger (2011 tv special) has a classical surviror telling a story that sounds awfully familiar to his listeners.
Now I'm curious myself.