Lee's parents died when he was a child. When he was a street child, he befriended Kazuya. Seeing this friendship Heihachi adopted Lee when he was 12 years old. He did this only for giving Kazuya a rival. Heihachi did not care about Lee and only used him to irritate Kazuya. This caused extreme harted between brothers. Lee studied fighting with Paul Phoenix and Marshall Law in the U.S. Everyone who knew his power, called him "Silver-haired Demon".
Lee joined to the first King of Iron Fist Tournamnet to defeat Kazuya, but he lost. He is the middle-boss of Kazuya's story mode.
Kazuya defeated Heihachi and took charge of the Mishima Zaibatsu. Lee sank into a deep depression and ran to the mountains. This anger caused that his technique to falter. Then an old man saw this and began to train him. Thanks to him Lee regained his technique. Lee killed the old man, because he was feared that he will say Kazuya about his plans. When he returned to the Mishima Zaibatsu he became Kazuya's secretary, and he did this only to be in a good position and later defeat his brother. Convinced by Wang Jinrei, Lee joined to the second King of Iron Fist Tourament. During the tournament he met Heihachi, who was really angry with him for helping Kazuya and defeated him. Heihachi killed Kazuya and took over the Mishima Zaibatsu. Lee was expelled for treason.
Lee was absent in Tekken 3. It is explained in Tekken 4 that instead of letting the hatred consume him like it did Kazuya, he realized that it was a waste to murder an old man, who probably had only a few more years to live, so he gave up on his plans to kill Heihachi and moved on with his life and left Japan for America, distancing himself from fighting and going into seclusion, amassing his large fortune in solitude. He grew bored of his rich lifestyle during his early fourties and he regained his old hatred towards the Mishimas and love for fighting.
After Lee sided with Kazuya in Tekken 2, he was expelled from the Mishima Zaibatsu by Heihachi. He thought of revenge for a long time, but he realized that is pointless to kill an old man and reformed. So he moved to a mansion in the Bahamas to lead a solitary life. One day he discovered a huge sell of G Corporation' stock online. He learned that the Mishima Zaibatsu attacked G Corporation and caused big damage. He also knew that Heihachi was searching for a main component needed to complete one of his project. In the same time The King of Iron Fist 4 was announced. His passion for fighting was rekindled along with his harted of the Mishima clan. However, there was also another important reason for his entry into the tournament. Lee believed that he could turn his humanoid robots into the ultimate fighting weapons. He believed (and still does) in a utopian world where inorganic humanoids would carry out the will of their human masters. Lee accelerated the development of the prototype of the first Combot for the Tournament. Lee decided to enter the Tournament in disguise, that the Mishima Zaibatsu not discovering his true identity. He signed up under a false name Violet, dyed his silver hair purple and wore sunglasses and violet clothes.
Lee met Kazuya in previous tournament. Surprised that he is alive Lee lost his focus and the fight. When Heihachi dead, Lee planned to take the Zaibatsu, but someone was faster. He was sure that was Kazuya. When the King of Iron Fist Tournament was announced Lee decided enter to this and finally defeat Kazuya and take charge of the Mishima Zaibatsu.
Lee joined to King of Iron Fist Tournament 5 to take revenge on Kazuya, but when he learned that tournament was opened not by Kazuya, but his grandfather Jinpachi Mishima returned to his home in Bahamas. Soon the Mishima Zaibatsu led by Jin Kazama brought the world in chaos and the G Corporation become a main opposition. Surprised Lee conducted a private investigation and discovered that Kazuya is behind the G Corporation actions. Lee entered to King of Iron Fist Tournament 6 to get close Kazuya. During that time, in the Scenario Campagin, Lee meets his adoptive younger brother Lars Alexandersson and helps him take down Kazuya, G Corporation, Jin and the Mishima Zaibatsu. After Lars stops Jin, he brings Lee a critically injured Alisa Bosconovitch and the latter promises to fix her.
Lee had Alisa repaired in time and removed some of the command system the Mishima Zaibatsu implanted on Dr. Boskonovitch's robot that was exclusively commanded by Jin.
Lee remains a supporter of his brother Lars, even when Heihachi returns to claim Zaibatsu. At some point, Lee goes to a restaurant and meets up with an investigative journalist who is looking into the Mishima Zaibatsu's affairs. At Violet Systems, Lee reveals to the journalist about Kazuya's blood and the curse that it placed on the Mishima family. Later when Alisa awakens to see him, she becomes hostile as he mentions that her brain is still damaged. When Alisa continues her assault on him, Lee is forced to battle her. After defeating Alisa, Alisa's memory systems began to recover and goes undergone upgrade. After upgrading Alisa's body, both are attacked by the Tekken Forces and he becomes weak when he unintentionally breathes in the sleeping gas. Recovering, Lee teams up together with Alisa to fight off the Tekken Force and they escape together.
Lee then brings Alisa to the facility where Lars is keeping Jin, who is in a coma. When they are attacked by Nina, Lee hijacks the helicopter that holsters Jin and remotely destroys the facility as he, Lars and Alisa make their escape. Lee later reveals that it was his plan all along to lure the Mishima Zaibatsu to the facility and take out the Tekken Force there. Lee later introduces Lars to the journalist he met. During the fight between Kazuya and Akuma, Lee, Lars and the journalist watch in shock as Kazuya's devil form is exposed to the world by Heihachi via satellite before the Zaibatsu CEO fires a satellite death ray on the G Corp's headquarters where Kazuya and Akuma are. Later, Lee uses his spy satellite to locate Heihachi, finding him before his battle Kazuya in their final fight.
After the true death of his adoptive father, Lee stands on the rooftops of a destroyed city with Lars and Alisa, concluding that G Corporation has no intention of stopping the war. He and Alisa then watch as Lars dispatches Jin to find and kill Kazuya.
Lee is a cunning and ruthless fighter who can do everything to take charge Mishima Zaibastu and defeat Kazuya and Heihachi. He was even able to kill his master in Tekken 2 to achieve his goal. Despite this he sometimes seem a bit sympathetic. In the film Tekken Blood Vengeance, he appears as a minor character and teacher and ally of Ling Xiaoyu and Alisa Boskonovitch, giving hospitality to the girls in his mansion.
- Jinpachi Mishima - Adoptive grandfather
- Heihachi Mishima - Adoptive father
- Kazuya Mishima - Adoptive brother
- Lars Alexandersson - Adoptive brother
- Jin Kazama - Adoptive nephew