Heihachi Mishima is one of only four characters to appear in every single Tekken game thus far (the other characters being Yoshimitsu, Nina Williams and Paul Phoenix). He is the owner of the Mishima Zaibatsu in the original Tekken, Tekken 3 and Tekken 4 and can be considered the main antagonist in the series, with many key story developments revolving around Heihachi or actions related to him. He is the son of Jinpachi Mishima, the father of Kazuya Mishima and Lars Alexanderson, the adoptive father of Lee Chaolan and the grandfather of Jin Kazama, but despite this, the members of the Mishima family despise each other, with Heihachi's Tekken 5 ending suggesting he would like to kill all three of his closest relatives (father, son, grandson).
Heihachi was born as the heir to the rich, powerful, and well-respected Jinpachi Mishima, the head of the powerful Mishima Zaibatsu and a world-famous martial arts master. During this time, Heihachi married Kazumi and eventually had a son with her named Kazuya. It is believed that his wife Kazumi died while giving birth to Kazuya or not long afterward. Heihachi raised Kazuya harshly. Kazuya grew up kind and frail, perhaps due to the more loving treatment he received from his grandfather Jinpachi. At some point, Heihachi betrayed Jinpachi and stole the Zaibatsu from him. His motives for this act are as-of-yet unknown, but it can be speculated that Heihachi disagreed with his lack of aggression and his "soft" treatment of Kazuya. After assuming control, Heihachi began to steer the Zaibatsu into the military industry. Jinpachi attempted to launch a coup to retake the Zaibatsu from his son, but failed and was ultimately imprisoned underneath Hon-Maru where he remained for around forty to forty-five years, until the events of Tekken 5.
Finally fed up with Kazuya's "weakness", Heihachi tossed his son down a deep ravine, claiming that if he were truly his son, he'd be able to survive the fall and climb back up. Kazuya actually managed to do so, but only because his life was saved by Devil, after trading his soul for the power to kill Heihachi, the Devil Gene. To further motivate Kazuya, Heihachi adopted the Chinese orphan Lee Chaolan and he raised him as a rival to his true son. It's assumed that Heihachi didn't care about Lee at all and only used him to irritate Kazuya. Over the years, Kazuya traveled abroad and competed in martial arts championships, becoming an undefeated champion. Eventually, Heihachi decided to test his son's strength, and announced the first King of Iron Fist Tournament.
Many years prior to the first Tekken game, Heihachi Mishima tossed his son, Kazuya Mishima (who was just a child at the time) down a cliff, thinking that if he was to be the heir to the Mishima Zaibatsu he would have to be strong and fear nothing. Thanks to a pact made with the devil, Kazuya survived the fall and managed to climb back up the mountain and would go on to become an undefeated martial arts champion. Heihachi, wanting to both prove that he was the strongest fighter in the world and at the same time test his son Kazuya, announced The King of Iron Fist Tournament.
However, Kazuya defeats Heihachi and wins the tournament, taking control of the Mishima Zaibatsu in the process. After defeating Heihachi, Kazuya throws his unconscious father into the same deep ravine that he had been thrown into as a child.
After losing to Kazuya at the conclusion of the previous tournament, Heihachi is thrown down the same cliff that he threw his son down over twenty years prior. However, like his son, Heihachi survives the fall and climb back up the mountain. Heihachi immediately begins training harder then ever before, vowing to get back everything that he had lost. Two years later, The King of Iron Fist Tournament 2 was announced.
In Heihachi's canonical Tekken 2 ending, Heihachi defeats Kazuya, and thus wins the tournament. He then drops his son into a volcano, ensuring his demise. As he leaves the volcano by helicopter, a smile can be seen on his face.
After reassuming control of the Mishima Zaibatsu, Heihachi develops the "Tekken Force", the Mishima Zaibatsu's own military force. Fifteen years after the second tournament, while excavating ruins, the Tekken Force discovers something strange. They are then decimated by a supernatural force. Heihachi quickly realizes that this could be the legendary God of Fighting, Ogre. Upon learning this, he hopes to lure Ogre out to capture him. Shortly thereafter, a fifteen-year-old boy named Jin Kazama informs Heihachi that he is his grandson, and that his mother, Jun Kazama, was attacked and presumably killed by Ogre.
Heihachi deduces that Ogre has a thirst for powerful fighters, and trains his grandson in the art of Advanced Mishima-style Karate. Under the supervision of his grandfather, Jin becomes an exceptional fighter--perfect bait for Ogre. After four years of training, the Mishima Zaibatsu announces the King of Iron Fist Tournament 3. Heihachi plans to lure Ogre out by using Jin, and then disposing of his grandson, as he recognizes signs of the Devil Gene that Jin had inherited from Kazuya.
In Heihachi's non-canonical Tekken 3 ending, we see him in a helicopter, with Jin unconscious lying on a stretcher in front of him. A mysterious tattoo suddenly forms on Jin's forehead (a sign that he is about to transform into Devil Jin). Looking on with concern over having to face another Devil, he picks Jin up and tosses him out of the helicopter.
Heihachi fails to capture Ogre during the previous tournament. Although he makes his researchers collect blood and tissue left behind by Ogre, his attempts to create a new life form by combining Ogre's genetic material with his own results in failure; only someone with the Devil Gene would suffice. Unable to find Jin, Heihachi learns that Kazuya is being kept in storage at a cutting-edge biotech firm called G-Corporation.
Heihachi promptly orders his Tekken Force to raid G-Corporation in an attempt to steal the body. The Tekken Force invades and destroys the corporation's laboratory, only to be killed by a mysteriously resurrected Kazuya. After learning of Kazuya's revival, Heihachi devises a plan to get the Devil Gene he needs, whether it be from his son or his grandson. He announces the King of Ironfist Tournament 4.
In Heihachi's non-canonical Tekken 4 ending, Heihachi defeats Kazuya to win the tournament, and then tells him to come with him, if he wants to see his son. After leading Kazuya to the Hon-Maru, Heihachi allows him to see his son, imprisoned in chains. Kazuya is shocked, but before he can do anyhthing, chains are shackled to his own arms arms and legs, and he's imprisoned just like Jin. Though Kazuya attempts to break free, Heihachi informs him that those chains were made to inhibit the powers of the Devil Gene, and that he will lose consciousness in a matter of minutes. Heihachi then laughs and exits the building, and the screen displays text that states, "Thereafter, the world came to know an age of darkness...".
After being defeated by Jin at the Hon-Maru after the previous tournament, Heihachi and Kazuya are ambushed by a group of Jack robots. Heihachi and Kazuya fight them off as a team, but during the battle, Kazuya throws Heihachi at the Jacks, giving him a chance to escape. Trapped, Heihachi is caught in a massive explosion as the Jacks self-destruct, and he is presumed dead. Heihachi is not playable in the original version of Tekken 5.
In Tekken 5: Dark Resurrection, however, it is revealed that such an explosion would have killed a normal man, but not Heihachi. A month later, he learns that someone had taken control of the Mishima Zaibatsu and plans to hold the King of Iron Fist Tournament 5. Heihachi, having fully recovered, is determined to win the tournament to reclaim his empire.
In Heihachi's non-canonical Tekken 5 ending, Jinpachi, Kazuya and Jin all tied to a rocket while a countdown is in effect. They all struggle to get free, but fail to do so, and are subsequently launched into space. Heihachi, watching the scene from a distance through binoculars, laughs.
After being assaulted by the Jacks after The King of Iron Fist Tournament 4, Heihachi wakes up only to find out that The King of Iron Fist Tournament 5 has already passed. However, its not long before the next King of Iron Fist Tournament is announced, and Heihachi discovers that Jin is the new head of the Mishima Zaibatsu. He is infuriated and once again vows to get everything back.
In his Tekken 6 ending, Heihachi is seen in outer space ready to dispatch Jin and Kazuya. However, he is kicked by Kazuya, and the three all begin to float uncontrollably toward Earth's atmosphere and burn upon reentry. Ganryu, down on Earth, mistakes them for shooting stars and wishes for Julia Chang upon seeing them.
Heihachi has appeared in several games outside of the Tekken franchise. He is a guest character in the PlayStation 2 version of Soul Calibur II, just as Link is for the GameCube version and Spawn is for the XBox version. In the strategy RPG Namco x Capcom, Heihachi appears as one of numerous playable characters. He also appears as a playable character in the Capcom-developed Street Fighter X Tekken. In Death by Degrees, he appears as the final boss in Anna's mode. In Xevious 3D+G for the PSOne you can turn your ship into a flying, laser firing Heihachi by press Left, X, O, and Start simultaneously at the Title Screen. He is also unlockable in several of Namcos Smash Court Tennis games.
Daisuke Gori, Heihachi's voice actor in every Tekken game through Tekken 6, passed away on January 27, 2010. It was subsequently decided that Heihachi would appear as a younger man in Tekken Tag Tournament 2 with a younger voice actor. This incarnation of Heihachi is also playable in the 3DS game Tekken: 3D Prime Edition.
Heihachi Mishima is played by Cary-Hiroyuki Tagawa in the 2010 live-action Tekken film. He is the ruler of the Tekken Corporation and saves Jin after Kazuya's betrayal. He was seemingly killed, but it is revealed that he is still alive in a post-credits scene.