Tekken 4 picks up two years after Tekken 3. Heihachi and his scientists have captured samples of Ogre's blood and tissue to splice with Heihachi's genome and make him immortal. The experiment fails, since Heihachi lacks the necessary Devil Gene. Not willing to give up, Heihachi searches for his grandson, Jin Kazama, who does possess the Devil Gene, with Heihachi learning that the body of his son, Kazuya (who also has the Devil Gene and died twenty years ago) is stored in the labs of the Mishima Zaibatsu's main business rival, G Corporation.