I'm not the biggest fan of Yoona so i was reluctant to watch this drama even though it's lead was Kwon Sang Woo. I'm really glad i ended up watching it though. The acting is very well done. Sang Woo plays both people so well that it makes you actually believe they could be completely different actors. I feel like this drama really deserves more credit than its gotten. It isn't so popular because it claims to be about the two men that look exactly alike where as its really only about one of the men, and Yoona. Definitely worth watching. Very good movie. Make me respect Yoona a lot more as an actor as well.