Tae-joo is a villain in the film I Saw the Devil. He is one of serial killers and friend of Jang Kyung-chul whom they shared killings of a young women and Tae-joo ate some parts of bodies. he had girlfriend and accomplice Se-jung who cheated him with Kyung-chul. Tae-joo ownered a hotel to lured young women into victims and he prepped to kill his last victim, Tae-joo was beaten by Kim Soo-hyun who put knife on his knife and he and Se-jung were sent to hostpail. He was killed by Soo-hyun whp forced mouth opened after taunted him about his fiacee's family.