Two years ago, Heihachi failed to capture Ogre. He made his researchers collect blood and tissue left behind by Ogre and attempted to create a new life form by combining its genetic material with his own. The experiment failed, however, and Heihachi learned that he lacked the Devil Gene necessary to integrate Ogre’s genome into his.
In order to obtain the Devil Gene, Heihachi searched for Jin, who transformed into a devil during the last Tournament. During the search, Heihachi learned that the body of his son, Kazuya - whom he killed 20 years ago - was stored at a cutting-edge biotech firm called G Corporation.
Heihachi ordered his Tekken Force to raid G Corporation in an attempt to obtain Kazuya’s remains. They obliterated G Corporation’s laboratory, and the mission appeared to be successful. …That was until Kazuya, revived by G Corporation, retaliated and caused the mission to fail.
Heihachi needed Kazuya or Jin’s body to create the new life form. After much deliberation, an evil smile crept onto Heihachi’s lips.
The next day, an announcement was made for The King of Iron Fist Tournament 4, with the Mishima Zaibatsu as the prize.