There is an entertaining and sufficiently different vampire story here. The
main flaw is there are too many episodes. It should have been 16 at most. Some of the technical jargon is tiring. Many scenes walking along the corridors talking could have been cut. The dialog is quite well written in parts plus some funny moments are quite unexpected.
Ahn Jae Hyun looks like a vampire so he is well cast if he slightly underacts a bit. Better than overacting. His real life soon to be wife Ku Hye Sun is pretty here and her character is suitably feisty. Look out for a bright and cheerful Jung Hae In supporting role. Ji Jin Hee is a memorable villain smiling yet menacing. When he shows his anger it is effective. I liked that the bad guys were trying to do something for mankind if too ruthlessly. Unfortunately the ending isn't satisfactory by any means.