I never wrote a review despite watching hundreds of dramas but I had to leave one for this one!
I don't see any flaws to it! The story is captivating, actors are brilliant, you get really attached to the characters because they are realistic and well written. The fighting scenes are realistic and great as well, which changes from these drama were the main leads practically fly without breaking a sweat!
The last episode was so intense I realised that I was barely breathing!
If you like stories about the underdog, deep friendship and action, don't hesitate! But brace yourself ;)