The actors, the storyline, the whole concept of this drama. Everything amazed me. Even though its theme is a complicated one (it is a fantasy show after all) I think the writers did a good job at making it cohesive enough without as many loose ends as I was expecting.
The two main characters did an amazing job ever since the first scene. Their interactions felt real and were heart-warming. And her father's job was so interesting (I'm very interested in art and stuff so I really liked that part of the plot).
I watched it a while ago (right when it came out) so I can't write a proper review but what I can say is that it's definitely worth watching.