I haven't written reviews for any kdrama but for this particular drama I felt like I must write. Because this drama is beyond the expectation. It gets more and more curious as the story proceeds. Unexpected twists and every episode ends with cliffhanger, which makes you impatient to know the next episode. The storyline is so well written and so perfectly displayed that while watching it's impossible to predict what is going to happen next. even if you predict something but it turns something else. There is not even a single scene where you feel like skipping. Lee joon gi and moon Chae won share a perfect chemistry. No words to describe the way they have portrayed the characters. Their excellent acting leaves the viewers so emotional and touched. And it's incomplete if I didn't say anything about background music, because this is which makes you completely engrossed into the story and intrigued. It is a must must must watch drama.. Five star is too less for this drama.