So, first of all I would have to say that this is a good drama but it has its disappointments.

But let's first look at its strong points:
1. The acting was really good and I was especially impressed by Jo Bo Ah who did a very good job of acting the two very different sides of her character. I don't understand why I saw many comments/reviews saying that the two main leads didn't have any chemistry because I definitely didn't think that; I thought they were really cute together especially later on in the drama.
2. The OST was AMAZING !! It had these powerful and beautiful soundtracks that really added to the scenes.
3. I enjoyed the story and weirdly it had many resemblances to the Vampire Diaries, Twilight, Teen Wolf. The plot was also a lot darker than I thought it was going to be so that was a bit of a surprise.

Now let's look at its disappointments:
1. Although I liked the story, I felt that this was also the drama's downfall. Firstly, near the end they were dragging it out so much to the point that I was getting fed up and just wanted to move on. They could have definitely ended it earlier. Secondly, the fact that they suddenly decided to sacrifice Lee Rang at the very end, I just found that very bizarre and it backs my point up about them dragging it out for no apparent reason.
2. This is a very small point but I was disappointed by Kim Yong Ji's performance, I just didn't think it believable.

Overall, I think it is worth a watch but beware the last episodes!!
(p.s. I really loved seeing Kim Bum again as the last time I saw him was in Boys Over Flowers which was my first ever kdrama!)