It has a nice non-cliche start and the first arc has an interesting narrative. The second arc slowly goes down and from episode 80+ it resets back to cliche kdrama material. Dunno if author can recover the story from here on but I am not optimistic...so down voted from 5 to 3.
Update: the raws don't show any sign of hope for the story so I'm dropping it.
The Investigator of Mueller