The chemistry between the main couple is pretty intense. Oh Soo and Oh Young both play their roles well as 'broken' people in very different worlds that are equally scary. The secondary couple is just very cute. The bromance/brotherhood between Oh Soo and Jin Sung is really sweet, though I ended up getting mad at/scared for Jin Sung through a couple of his misguided choices due to 'extreme loyalty.' Song Hye Ko does an admirable job feigning blindness. Jo In Sung looks amazing in fashions that seemed to be lifted right out of American gangster movies based in the 20's and 30's. Besides the fact that he definitely looks the part of an attractive womanize, the man can also act. I spent pretty much all of the drama heavily sympathizing with and rooting for him, even while realizing what he was doing was highly questionable/just plain wrong. Kim Tae Woo was awesome as Moo Cheol. I definitely felt all sorts of emotions towards him as his story progressed. I just thought the story was beautifully acted and filmed. I was on my toes for the whole thing, and could not stop watching it until it was all over. It really got me out of my drama slump!