Lars Alexandersson is introduced in Tekken 6: Bloodline Rebellion and immediately becomes a main protagonist of the series. He is the main protagonist in the Scenario mode along with Alisa Bosconovitch. Lars has a heroic personality as he lead the coup d'etat into defeating the Mishima Zaibatsu, he has the fighting spirit and determination of his half-nephew, Jin Kazama, and the charisma of his adopted half-brother Lee Chaolan. Lars is the complete opposite to Heihachi and Kazuya in terms of personality.
Tekken 6: Bloodline Rebellion
As the Mishima Zaibatsu waged war on the world, its soldiers, the Tekken Force, began a worldwide coup d'etat. G-Corporation, lead by Kazuya Mishima, rose to power and was their main opposition, leading to worldwide conflict. The mastermind behind the coup d'etat was Lars Alexandersson, a young, chariscmatic Tekken Force officer with incredible physical ability and intellect. Most importantly, he is the son of Heihachi Mishima, and no one, save for Lars himself knows this. Not even Heihachi himself.
In the console versions of Tekken 6, and more specifically in the story-driven Scenario Campaign within, Lars is made the central character along with Alisa Bosconovitch. After an infiltration of a Mishima Zaibatsu-run laboratory goes awry and a series of Jack robots overwhelm Lars' rebel squadron, Lars is left with no memory and begins to seek out his true purpose. Joined by an activated Alisa, he crosses the world trying to grasp his identity. Along the way he meets a lieutenant in his rebel Tekken Force army who tries to enlist him to help the cause once more. Lars' memory is restored upon encountering Heihachi Mishima at his compound, at which point he also rediscovers his purpose. He resumes his role as the leader of the rebel Tekken Force army and infiltrates both G Corporation and eventually the Mishima Zaibatsu itself where he encounters Kazuya and Jin respectively. Before he is able to fight Jin at the Zaibatsu headquarters, it is revealed that Alisa has been acting as Jin's surveillance unit and has been monitoring Lars' movements around the world. He commands Alisa to attack Lars, to which she unwillingly complies as per her programming. After a fight with Lars, Alisa leaves to join Jin. At this point, Raven offers to accompany Lars and together the two pursue Jin into the desert where he intends to awaken the ancient beast Azazel. At Azazel's Temple, Raven and Lars collectively defeat the newly awoken Azazel and encounter Alisa and Jin one more time. Lars disables Alisa and engages Jin in battle but before he is able to finish his fight, Azazel reappears and Jin turns his attention to the monster. Jin destroys Azazel (seemingly at the cost of his own life) and Lars' mission is completed. He brings the disabled Alisa to Lee Chaolan, who offers to restore her. After leaving Alisa with Lee and parting company with Raven, Lars gets a call summoning him for a new mission.
Tekken Tag Tournament 2 (non-canon)
Lars sits down with the Mishima and Kazama families for something special. Jun's pot whistles and a massive dinner is ready. The rest of the family begins digging in at a rather fast pace while Lars is suddenly too slow. Lars almost makes it to the last egg but everyone's chopsticks break it. Lars barely has time to get a taste of seaweed only for Heihachi to eat it. Just then, Lars wakes up from his nightmare in his Tekken Force helicopter. After his bad dream, he asks for a bite to eat.
- A vast majority of Lars' moves are named after military terms or terms used in the field of electronics and electromagnetism. His fighting style hasn't been confirmed by Namco.
- He shares some physical similarities with Siegfried Schtauffen, a character of the Soul Calibur series, another fighting game series by Namco.
- Despite being Swedish, Lars speaks Japanese in all movie sequences making him one of the few Tekken characters to not speak their native language.
- Illegitimate son of Heihachi Mishima, which Heihachi was unaware of until their meeting.
- Half-brother (agnate/cosanguine, same father, not mother) of Kazuya Mishima, who figured out they were related after exchanging blows.
- Foster brother of Lee Chaolan.
- Grandson of Jinpachi Mishima.