Okay so first of all it's so hard not to be bias with this drama because you know, Myungsoo <3 haha but nevertheless, here's my two cents:

I would just like to say, hats off to Lee Yeon Soo her life is full of ups and downs. It's the perfect example of a roller coaster life. If I was in her position I wouldn't know what to do. And hands down to Shin Hye Sun, she's truly an excellent actress.

Plot wise I was surprised by how fast the pacing was. If I can remember correctly majority of the "secrets" were revealed in the early episodes of the drama. But even though a lot was revealed already, they still managed to keep it interesting for the viewers to continue watching. The further the story went on, the more complex the emotions were depicted. However, the thing that impressed me the most in the story line is that, they were able to impart the viewers a very valuable lesson that is usually not highlighted in shows these days and that is "true love can be received from various people not just your romantic partner". To be honest, I thought Kim Dan turned into a human when his senior sacrificed himself to save Dan but I was glad it didn't happen immediately then because the montage of the different efforts the couple has received to help Dan become a human was really heartwarming.

However, there are a few reasons why I gave this drama this score and not a higher one. First is I'm not really a fan of the acting of Do Ji Won in this drama it seemed over the top. I've seen her in other dramas and I know she can do better. Second, I don't think Myungsoo was the right choice for Kim Dan. Yes I said it, don't hate me I have my reasons for this. Don't get me wrong I'm a huge fan of his but I'm not quite sure that mature roles like this suit him just yet. Yes, his acting over the years has improved but personally I think he is not yet in this level. Also, I think he is just too good looking. Every time he cries I find it hard to feel compassionate with his character because I get so distracted by his perfect face.
Lastly, there are just a lot of loopholes in the plot that I can't even remember all of them. I think they shouldn't have had Ji Kang Woo fall in love with Yeon Soo without any backstory of how he met her because by making him truly fall for her , it will seem that the love between JKW and Seolhee was not that real and the sacrifice of Seolhee turned out not that meaningful for JKW.

To wrap things up, I'm not regretting that I have watched this drama but I don't think I'll be rewatching it any time soon.

PS: I was surprised at how good Myungsoo is with kissing scenes <3 Honestly made me fall for him more lol. If I can't have him I'll settle for a clone of his hehehe jk.