Amazing, my favorite drama. I don't think I'll be able to even do this drama justice in this review, just go watch the show.
I initially only began watching this because it's one of the only dramas Hulu has. I'm not a fan of dramas with the rich guy and poor girl dynamic because, I typically find that they demean the girl the entire time, but this one was so different. Not because they didn't demean her, but because the story strengthened her.
Is the story dramatic? Yes. Unrealistic? Yes. Does it have ridiculous moments? Absolutely. But, do the actors do so well that you feel as though it's all real? YES.
This drama not only is entertaining to watch but also has life lessons and morals that may impact your real life (as it did mine).

Storyline:
This drama, as most know, was adapted from the Taiwanese version and in all honesty, I'm not trying to hate on the Taiwanese version, but I couldn't barely get through the episodes of it. In my opinion, it lacks the charisma and heart wrenching value that the Korean version has.  

The storyline sounds so cliché and terrible, but this show makes it work and uses the tropes in a unique way that makes them no longer tropes. It has it's overdramatic moments, but what drama doesn't? To add to that, even the overdramatic moments are so well executed ( in my opinion) that they makes you emotional.

Acting/Cast/Characters:
Gunnie. Oh Gunnie. He truly makes the series as good as it is. He isn't a super stereotypical lead and I feel as though this is one of the reasons that despite the fact that the story has tropes, it continues to be extremely unique. After you watch this you'll probably be imitating his ridiculous laugh for days. That said, he's a character that'll make you roll laughing but also cry your heart out. His genuine heartbrokenness over some of the serie's events is so realistic that it's even more heart wrenching for the viewer to watch. There is so much I wish I could say about this character, but it'd be a spoiler and so I won't say those things. But, he is just all in all a beautiful character. The one thing I will mention from later in the series (and I won't spoil anything) is the computer videos scene (those who have watched the show know what I'm talking about), I have never ever cried so hard at a show or movie as I did watching that scene. It was so realistic and relatable and heart destroying, especially when he's talking about being in the restaurant and choking on the food (again, sounds weird, but those who've watched know what I'm talking about.) it was so relatable.

As for the female lead. Amazing as well. Being a "post-it" girl myself and seeing the character naturally form into such a strong, independent woman was amazing and gave me faith for myself. Jang Na Ra's acting skills are off the charts, I don't really cry at movies or shows. Ever. But, every time she started sobbing, so did I. And this is partially because Jang Na Ra (and Jang Hyuk as well) didn't do the whole "pretty cry." When she cried it looked so real and even though she ugly cried it was beautiful and brought out so much more emotion than when actors do the pretty, delicate cry. When Gun and Mi Yeong cried, they SOBBED. And so did I.

The "love rivals" in this were good as well. I loved Daniel and Se Ra's side story, it was heart warming and I'm so happy they got a good ending as well. Last but not least, despite the two main leads being AMAZING characters, in my heart two supporting characters may be tied with Gun and Mi Yeong as my favorite characters in this series. Those two characters are Manager Tak and Yong. Them as a duo was HILARIOUS. Yong's funny facial expressions and reactions had me on the floor laughing. Both in seriousness and in comedy view Yong was the character I related most to, where as Tak was amazing again, both comedy wise and in caring so much for Gun and Mi Yeong as well.  Bottom line: even with as good and I find the storyline to be, had they not casted the actors they did I don't think this show would've been even half as good as it is. The actors and the characters they played were absolutely amazing.

Music:
I just have three words "Goodbye My Love." That song was stuck in my head for days after watching the series. As if the sad scenes weren't sad enough, this song would start playing and I'd begin tearing up already. Ailee's voice (which I actually didn't realize it was her singing it til after watching the series) is addicting and pure gold. As for the other tracks, they were fantastic and fit the scenes so well.

All and all, this series is SO worth your time. Don't write it off because of the synopsis.