After the conclusion of The King of Iron Fist Tournament 4, an intense battle between father and son, Kazuya and Jin, took place at Hon-Maru in the Mishima Zaibatsu headquarters. Jin emerged as the victor, and Heihachi turned his back on Kazuya and said.
"What a pathetic wretch... You worthless coward!"
The battle between Heihachi and Jin began. Jin defeated Heihachi. Filled with anger, his black wings spread, Just as Heihachi thought he was doomed, Jin regained control of himself.
"Thank my mother, Jun Kazama." Jin said as he took flight.
The sounds of battle gave way to silence as Heihachi lay spread out on the ground. The silence was soon interrupted by approaching aircraft. The roar of the aircraft increased and the sound of something being ejected was heard. A group of Jack-4s crashed through the ceiling. At first, Heihachi suspected that Kazuya was responsible for the intrusion but realized that Kazuya was just as bewildered by the sudden attack.
"Why are you here?" tells Heihachi as the wave of Jack 4s approaches. Heihachi and Kazuya team up and battle waves of Jack 4s but reinforcements appear as fast as the Jacks are destroyed.
Heihachi starts to lose his breath. Kazuya then betrays Heihachi, throwing him into the middle of the army of Jacks, and uses the opportunity to escape from Honmaru. Shortly after, Honmaru is devastated by a huge explosion and Heihachi goes flying, landing in a graveyard
On an airplane close by, the battle is watched by a man dressed in black. He raises his hand to his ear and speaks into his radio.
"Heihachi Mishima is dead..."
At that moment, a Jack attacks from behind but it cut in half instantly as the man disappears.
Hon-Maru is completely destroyed, a raging inferno in its place. A pile of debris was blown apart as something emerged from the earth, unseen.
The next day, news of Heihachi Mishima's death spread rapidly across the globe. Most people believed that Heihachi's death would bring about the end of the Mishima Zaibatsu, but behind the scenes someone else had taken control, and business went on as usual.
A month later, it was announced that the Mishima Zaibatsu will hold The King of Iron Fist Tournament 5.