This drama already got lots of review but I just want to share my own opinion on this.

The story is mind blowing. I love that I got to see the point of view from all sides. I have nothing more to elaborate other than the story/plot is amazing. So congratulation to the screenwriter, Ms/Mrs Lee Ah Ram, for creating this amazing story.

As for the cast, let me start with our hero, Jang Ki Yong. I've heard of him before but I've never watch any of the drama he's in. And wow, what an introduction to this incredible actor. He is amazing as Yoon Na Moo/Chae Do Jin, this character in my opinion is very hard to portray because Na Moo doesn't show too many expression on his face but instead you can clearly see everything he's experiencing through his eyes. He mainly conveyed his emotions all through his eyes. Whether he's happy, sad, angry, anxious, excited, worried, a little crazed up, you can see it all from Jang Ki Yong's eyes.
And of course, through Nam Da Reum's eyes too. This boy is going to be a top actor in the future, mark my words. Nam Da Reum managed to portray such mature and calm vibes. While watching both of them as Na Moo, all I want to do is protect them both and hug them. Na Moo is such an incredible character and they both nailed it.

Honestly, I've never heard of Jin Ki Joo before. After looking at her drama list on MDL, it's no wonder why she escaped my radar, it's because I didn't watch any of the drama she's in before. She's such a great actress and she's beautiful and cute as heck. What I love the most about Jin Ki Joo is her voice, it's very soothing. I absolutely love Ryu Han Bi. She's an amazing actress and she's sooo gorgeous. I am so looking forward to when she's an adult and will become the main lead in the future :) I have my fair share of kdrama in my life, so far in my opinion, the only best heroine ever is from While You Were Sleeping. But now Gil Nak Won/Han Jae Yi just join the club because I love Nak Won so much. She's strong and she's not scared to defend herself. Nak Won is so understanding towards Na Moo. And watching them together makes my heart ache.

As for the other actors, they all did an amazing job. And the music suited the drama so well.

The romance between Na Moo and Nak Won is so spectacular. Their love withstand all the bad things that happen to them. Watching them together is so beautiful. Jang Ki Yong and Jin Ki Joo have a very great chemistry, it's off the chart. And of course, Nam Da Reum and Ryu Han Bi too. I will be on the lookout for this 4 actors <3

I recommend this drama to someone who is not afraid of dark romance theme.