I'm super sad to rate this drama with only 5 stars, but here we are. If I'm being honest, even these 5 are given for the beginning glory (the first couple of episodes pulled me in), and also because of fantastic Woo Gwang-nam, and cutie Kang Hae-jin.
I really wanted to love Jung Ji-ho, because I really like Go Kyung-pyo. However, I could not bring myself to like his character this time around. There were too many red flags in his behaviours [spoiler](e.g. deciding things concerning Sang-eun's life without even discussing with her first, withholding truth etc. All the while Sang-eun was super annoying in her own right!),[/spoiler] and then some romance that felt kind of forced.
The dialogues were mostly redundant and boring. It seemed like the writers lost their direction pretty quickly, or forgot their intention. A lot of times a Kang Hae-jin scene would appear out of nowhere, completely disconnected from the rest of the plot, looking like a candy you would toss in front of a child to make them forget you're supposed to be telling them a story.
Scenes that were intended to be touching, endearing and cute between the two main characters felt strange, awkward and somehow artificially fabricated most of the time (I do realize this is a tv show, so by definition it is a fabrication, however, it shouldn't be obvious unless for comedic or similar purpose).
I could probably list many more grievances, but I'll stop here.

p.s. I believe the cast did the best they could with what they were given.