"Is Detective Kim a Hero or a Devil?
Detective 'Woojin (20s/M)' is a psychopath devoid of empathy and moral compass. But, He is a traffic officer at Seoul Central Police Station.
Due to his adeptness at concealing himself, his colleagues can't realize that he is a psychopath.
One day, Woojin goes to support a violent crime scene and witnesses a gruesome murder, intuitively sensing that the killer is the same person who murdered his parents.
As he awakens to his deeply repressed horrific past, he remembers that he wasn't transparent and was not killed.
Becoming an invisible man, Woojin successfully solves cases at major crime scenes, earning a promotion to a detective in the violent crime division.
Now, determined to avenge the murderer who took away his life, he decides to live a dual life as both a 'detective' and a 'killer'."