On the surface it looks like a common revenge theme drama, but it is a lot more. Case could made about various flaws of this - story too focused on main pairing, a simplistic story, not too much going on. In spite of these flaws this has been a mesmerising drama for me.

I was already a lot excited as it was Pyo Ye Jin's first drama where she takes a spot among first 2 leads in MDL casting list. Needless to say I've liked her role a lot in Taxi driver, Our blooming youth. I wish her luck for future successes.

Now coming back to this drama. It starts with your usual bickering ML-FL, but it takes a sudden turn. And we are introduced to their past lives. ML is a military general mired in a battle against rebels. And FL of course is somehow related to rebels. This is the past connection. Story goes forward, ML dies and blames FL for his death. He takes a solemn vow to exact revenge on FL.
Now, it's not a typical revenge. And this non-typicality of it makes it such a decent drama.

I initially gave it a 10 after first 4 episodes, but was heavily let down by second half. Major flaws of the drama would be the:
1. The unnecessary storyline of Han Min Oh
2. The execution of the past foster father's revenge

After introduction of above 2 storylines, even the main romance plot lost its lustre.

If you want to watch this drama, it's very good in first half. Rest you can skip or skimp.