This drama has an original story, relationships, characters and it is so addicting! I just finished rewatching it!
If you search for a drama with a different approach (all mostly have the same approach) on EVERYTHING and you want to see a strong female lead who actually fights and is ruthless to her enemies, then you have to watch this. Also, it is supposed to be a medical drama but it focuses on the female character's development so it isn't really a medical drama... It has lots of medical scenes but it's not the main point of the drama. I definitely loved this and I recommend it!

There might be some little spoilers below so if you don't trust me on this and you need more info to go and watch it, go ahead and keep reading.

It might not be a 'full medical' drama but I believe it is original and the characters development is so entertaining. It is one of the few dramas (actually it's the only one that comes in mind) where one of the main characters actually goes for revenge instead of doing nothing and just enduring everything the bad characters do. It also shows the side effects and outcome of revenge. In all the dramas that I've seen until now , the main characters are good guys that endure everything and keep defending themselves but not attacking the opponent so I always wanted to see what would happen if the characters actually take revenge. Well here we go! Not only that it happens in this drama but it also shows the outcome of it and how it interconnects with other people!

I definitely enjoyed the female lead's development during this show because honestly I'm so fed up with powerless, ignorant, stupid characters with 'good girl syndrome' that always need another character to pick them up from the ground when the bad guys act up (even if even here, the guy saves her.. but if you'll watch the drama you'll know what I really mean).
I've seen people being unsatisfied with Kim Tae Hee's acting in this drama for not having expressions but I think she did a good job here playing a complex character. Most of the time she's either filled with affection for the male lead or she's dead serious trying to be a step ahead of the bad guys. Maybe that's why people complain about her expressions but based on her character's story, that's what she should express..

As for the love story, it is different from other dramas. It might not be very deep love story for some people but it's pure and considering that the female lead is 'dark' and full of hatred, the male lead is the light that completes her and gives her a reason to smile. I honestly liked this approach on the love story and that even if the male lead slowly found out how dark she is, he didn't feel disgusted by her but tried to get her 'on the righteous path'. Did he succeed? Watch the drama and see for yourself.

When it comes to music.. I honestly couldn't pay attention to it because the plot really caught me.. I don't even remember hearing music during this show.. Sorry I can't comment on that but I'm a fan of kdrama osts so the music should be amazing as well.

Everything happens fast in this drama so you can't get bored.. you start the first episode and then BAAM you happen to finish the series and wonder what to do with your life. It is entertaining and unique. 100% would watch again in the future.