I started watching this series because I found the plot interesting and the reviews were also recommending it. I found the first few episodes a bit slow, and leaving the inconsistencies aside, I think the story developed pretty well up until episode 12, but from there things started to go downhill. Everything seemed to be on fast forward post episode 12, the scenes had no flow in between, the story started to make no sense, things weren't explained anymore, they just happened, the cringe started to kick in and ended up with a last episode that was supposed to patch things up somehow, but personally it was like watching a bad comedy. There were also inconsistencies in the last 10 minutes of the last episode - his sentence versus the last scene doesn't make sense. And the last scene - I understood you wanted to show it's winter time, but in what normal house it's so cold that condensed air comes through your mouth when you speak?
My second problem with this series was the main female lead. I don't know how she played in other dramas, but here she was grasping for air at least once per minute when she was on the screen. The constant panic and hyperventilation she showed throughout the series were very annoying. Plus, her character was one of the dumbest female leads I've seen in kdramas. It seemed like a little kid who saw a candy and would pursue it no matter what, without looking right or left, just to have it. She never learned from mistakes, always had to be saved and managed to say so many "Oppa"s per minute/phrase, that I have seriously considered muting the sound each time she and male lead were interacting. And *spoiler alert* there was a scene where the roof fell on her boss, he jumped to save her, got injured and she walked by to check if a total stranger is alive or not, without any "thanks" or "are you alright/injured?". That left me speechless - what kind of human being does that? You want to save others so much that you discard everyone else who's close to you? Makes no sense to me.
Leaving aside the many things that didn't make sense and we never got a valid story for, the male lead, 2nd male and 2nd female characters were ok and did the job as best as they could. The additional 2 grim reapers had their funny moments too and at least made the show bearable after episode 12.
Overall, I wouldn't recommend this drama to anyone, unless you have time to spare.