This isn't one of the best kdramas, but it has two likeable stars and they keep you watching.
The first half of the series focuses very much on the love affair between those two stars, with various obstacle needing to be overcome. If you like a good romance it is likely that this will offer sufficient traction to get you engaged.
As we enter the second half, the core relationship has reached a kind of equilibrium and thus offers less dramatic impetus. So the focus shifts away somewhat to other plot strands, most particularly some hospital management shenanigans. Unfortunately this transition is a little grudging, much time still being dedicated to the central couple, meaning that the drama from those other plot strands can be a little undercooked.
But still, if you like the central couple you will want to keep watching.