This is the first time I wrote a review on a drama. Yes, this show is that good. The best drama ever. Everything is so perfect. This is the first JCW series that I've watched, and I fell in love so hard in the first episode and been fangirling ever since. Watched it back in 2015 and I wondered where have you've been in my life all this time JCW???
The story is perfect, the plot twist, the details, and the romance... First time I watched kdrama that has romance which is so natural and well built. Perfect portrayal of the character. Every character has its own strengths and flaws, even the main character that we thought just as plain cool for the first time, and that's what makes it real. No love triangle (which usually appears in every kdramas), no unnecessary conflict (sometimes kdramas make us asked, oh waaee...), no amnesia (LOL), happy but not too over ending, kinda rush a bit but that's okay. It's getting better when I watched it for the second time. I can understand the character much better and I can put everything right in the place.
If you haven't watched it, that's your loss. If you have, watch it again. It feels better every time.
I don't understand why the rating is considered mediocre in SK itself, maybe because of a lack of promotion. Such a pity. This show is a gem and you are lucky to find it.