I've seen the high score of this drama and I was really sceptical. I don't like real dramas, but this...IS GOOD!!!
The story, the acting, the directing and the music and everything else....oh my... it's is like you are part of that story. And the end was as it should be. Everything is so natural that it makes you fill like is your story/life too.
You need a few boxes of tissues...but you'll be OK.
I watched quite a few KDramas and I always hated that they brought the story to an end in the last 3 minutes, but this one it leaves you building the end and what is to come the way you want it. It gives you a "path" but that path can split into more, leaving you crying and smiling, thinking "That's the way it should be".
Watch it and you will not be sorry.