I loved the story line. It was gripping and to me, also racy. It could have been worth of 10/10 but there was too much emotion for me. I kept thinking that they are spies and should act like one. If the spies were more honorable and not so sentimental it would have been great story! :) I'm not so good to criticize acting but if I have to say something I'd say it was good. At some points I felt like they weren't 100% in the character but mostly they did a good job. I think Eric Mun was great choice for Gang U. He's handsome and his voice melts me ;) I loved Jang Hee Jin's acting, it was great and she took over the role! :) Only thing that I'm not sure about was if viewers were suppose to hate or love Kyung Joo's character. Because if we were suppose to like her, it wasn't a good actress choice.. At least I hated her for the whole time. She seemed contrived to me :/ Music was great, I loved it! :) When watching the last episode I was able to sing along. And that's -dear MDL users- not something I usually do :) I would like to watch this again if I had time. At least all those episodes before they became too emotional. There were couple scenes which took place in my "all the time favorite scenes"-list (; Overall; as mentioned before it was better in the beginning. I liked the idea of them being spies on a mission. I wished more spy-like-action. There were couple of too cliche scenes but I made through it with a smile :) In the end, I'd like to say that I liked this very much. Many nights I spent thinking what would happen in the next episode. Many time I pulled my hair because there were no preview of the next episode. Many time I screamed to the characters to help them out of a difficult situation :) Definitely was worth to watch!