Just finished the drama and I have to say I think it is probably gonna end up being my favorite drama of this year.
Story:
The story is soooo unique. I love time travel dramas in general, but have never seen one even a bit similar to this one. The main character Otaro/Eight is a complex character, and is very manipulative. I love him, and sometimes I love to hate him; he is so intriguing throughout the whole drama, and the way his character develops and changes throughout the drama is amazing. With Otaro being such a unique main character I think you could suspect the romance isn't quite like other dramas. The romance is different and is not very lovey dovey, but it is still verrrry good, their chemistry is just amazing. I would have to say this story's focuses are mystery, manipulation, changing for the better, and lots and lots of twists (as to be expected in time travel dramas). Everything is so well crafted.... I just love it.

Acting/Cast:
The casting for this was just perfect, I think the actors did an amazing job.

Music:
I have no complaints with the music, and I loved the theme song. Just great music in general.

Rewatch Value:
I don't really rewatch dramas, however I do think I will probably rewatch this when I show this to my sister. I show her some random dramas I think are good, and I think this is definitely next on the list.

Overall:
Great drama, please watch it. You won't regret it!