I've watched this twice already, and I can't keep tearing up at the heart-wrenching story between the 2 between fighting for their fates, forgetting their memories and choosing life over their love.
The one thing that made this drama a great hit for me is the chemistry between KHY and BWS. Their delivery is also the best. Their facial expressions gave away their lines. I've seen so many Korean actors and actresses who fake tears or crying by wailing and pretending they are crying without a single teardrop and it makes the drama funny instead of sad. But these two are really versatile.
The production team really did a good job casting the right actors. If I can give a perfect score I'd give 11/10 for this drama. It's heart-wrenching and so full of romance despite the unrealistic time travel. It reminds me so much of how sad the Time Traveller's Wife was. Good job, KHY and BWS and all the staff and actors. <3