Omg, this drama is perfectly nice. I always love action drama. Killing, suffocating, spying and those actions inside a korean drama.
City hunter is the best, but then there's one korean drama almost the same like this which I forget what it is called but it was starring lee junki ;D
Here, it's starring Lee minho, and I think it suits perfectly on him !
You will regret if you don't watch it.