The King of Pigs

Two friends in the past were victims of serious school bulling. One could not resist his trauma, and becomes a serial killer, walking in the path of revenge. Another one tries his best to overcome the trauma and becomes a police detective. He now faces tragic fate to risk his life to capture the serial killer.

Both dramas masquerade under the guise of a classic revenge tale to tell a bigger, yet more personal story. They both focus on two male leads who have been connected through childhood (and there are many other similarities that would be spoilers).