After 106 episodes. I've given up hope of any improvement. There are no longer any plot threads, just gimmicks to stretch it out longer. I started it because I enjoyed Shim Yi Yeong in Want a Taste, which, as daily dramas go, wasn't awful - interesting characters and decent writing. But I found that this was going to be a re-run of her character in that one, the beleaguered, unappreciated goody goody who takes care of everyone. I should have quit at that point.
The characters in this drama had potential but were stagnant throughout. No one learned from their mistakes, no one improved. Do I think that will happen with 12 episodes to go? No, but if it does it will be totally unconvincing and rushed. The acting, especially of Jin Ye Sol, was positively dreadful. She seems to have two expressions, neither pleasant, and I was tired of her scowl a long time ago. She's written as the most two-dimensional, stupid villain ever. And as near as I can tell, there was no real development in the male lead. He and Shim Yi Yeong did not seem to have any believable chemistry at all. He didn't come across a a competent corporate type and seemed under developed throughout - not sure whether bad writing or mediocre acting was the reason, maybe both.
Poor writing paired with mediocre to bad acting earns this a spot on your "Don't bother" list.