Lee is the Chinese adoptive son of Heihachi Mishima, whose own son Kazuya's defeat is Lee's motivation for entering the numerous King of Iron Fist tournaments held throughout the "Tekken" series. Lee was adopted by Heihachi to provide a rival for Kazuya, who he felt was too weak to lead his Mishima Zaibatsu company. Lee studies in the United States alongside Paul Phoenix and Marshall Law. After Kazuya wins control of the company, Lee works as Kazuya's secretary, in addition to overseeing Kazuya's team of bodyguards and Dr. Bosconovitch's experiments, all while secretly hoping to take over the Zaibatsu. However, Lee is soon expelled from the Zaibatsu for unknown reasons while Heihachi disowns him, causing him to leave the world of fighting and pursuing a career in robotics.