[Spoiler] this movie and the first two episodes (1&2) of the drama are shareing the same theme, about one crazy man fascinated by beauty, so he kills women to creates his own woman from other bodies (the parties of his victims).
In I saw the Devil a man is getting revenge from the serial killer who killed his wife and unborn child. In The Five a lady gets revenge from the serial killer who killed her family. Very similar plot but with different ways of getting the bad guy.
Psycho Ohn Joo Wan! One of the reasons that led me to watch this drama immediately while it still broadcasting was Ohn Joo Wan, again in a crime drama after The Five.