Tae-joo is a villain in the film I Saw the Devil. He is one of serial killers and a friend of Jang Kyung-chul with whom he shared killings of a young women with Tae-joo eating some parts of bodies. He had girlfriend and accomplice Se-jung who cheated on him with Kyung-chul. Tae-joo owned a hotel to lure young women. As he was preparing to murder 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 hospital. He was later killed by Soo-hyun who had forced his mouth open after taunting him about his fiancee's family.