To tell the truth I have a really ambiguous opinion about this drama. If I didn't know that it's based on a novel, I would say that it's a clear copy of Goblin: a similar supernatural love story of a woman and a supernatural being united by the fate, a bromance between two supernatural beings living in the same house but actually being enemies (incomparably more charming and subtle in the case of Goblin), the atmosphere, etc. In such a situation I must say that Goblin has a much higher quality in all aspects (including the acting, undoubtedly). But... I've give ten for the acting in this drama. Why? Well, I've never been a fan of Lee Seung Gi, he always seemed to me a bit too much immature but here his character is almost impeccable. Also I must say that there are quite a lot charming, impressive, unexpected moments in this drama which don't let you simply drop the drama. Somehow you keep remembering its atmosphere, some moments, the acting... So I resign and admit that I really enjoyed it ;) (although if there are quite a lot of scenes with an akward humour... :/ )