Having watched just the first episode much can not be said, the plot was refreshing and was different from the ones I usually watch (a lot of rom- com). I am in a stage where I usually skip the parts with a lot of gaps but despite that the cast and the progression of the story put me in the edge of my seat, making me want to watch every part of it. The preview of the next episode gave me a feeling of rush that made me curious and it kind of sealed the deal for me to continue to watch it.
Nam Ji-Hyun is one of my favorite and she did NOT disappoint. She managed to deliver the emotion of the character perfectly. (I am sorry because I do not know the rest of the cast very well)
I do not advise you guys to read the review of the Japanese version because it might be a put off to watch the Korean version.