- "It feels good to be back. Hiding in the shadows after you feigned your own death is a bore. In fact, it's downright tedious."
- — Heihachi Mishima to his friends, before Crash Gordon appears.
Heihachi Mishima was the main antagonist of Tekken: Blood Vengeance, as he killed Shin Kamiya via a "jumping backbreaker" before visiting Rockoland (He was revived at the end of second episode.). It was revealed that he lost the role of the main antagonist to Crash Gordon.
In the second episode of Alisa's Adventures in Rockoland, he became happier than ever because he received his very own robot, otherwise known as the MishimaBot. It was revealed that the MishimaBot is also Heihachi's best friend. This is because Heihachi never leaves home without his MishimaBot.
Heihachi said things that were "downright tedious" throughout Alisa's Adventures in Rockoland, including:
- "Hiding in the shadows after you feigned your own death is a bore." (Tekken: Blood Vengeance/Alisa Meets the Squad)
- "You know, having no robots at your home is a bore." (Rockobot Rampage)
- "These sleeping girls... That's just a bore to you guys!" (The Cannon, the Spader, and the Sleepy)
- "I was lonely at home, and that was a bore." (Makoto Comes to Rockoland)
- "But we can't have any snoring. That's a bore." (Alisa's Daydream)
Also in Alisa's Adventures in Rockoland, he was very sad when his father, Jinpachi Mishima, used all of his Kyoto Arcade tokens to get some things for the Mishima Zaibatsu, and then he mentioned that Kyoto Electronics closed down, followed by Heihachi crying. Heihachi is the second male character from Tekken: Blood Vengeance to cry at least one time in the Rocko franchise, after Jin Kazama. However, he stopped crying when Sammy gave him more Kyoto Arcade tokens. It was then revealed that Crash Gordon forced Kyoto Electronics to close down, but Alisa Bosconovitch forced Crash Gordon to re-open the store after he was defeated. Heihachi's Kyoto Castle entrance laugh is always preceeded by various lines. This list shows all of the lines said before Heihachi's laugh (all of these are said by Evil-Man unless noted):
- "The stage has been set." - Tekken: Blood Vengeance (Shin Kamiya)
- "GIIIIGAAAA CUUUURSES!" - Barney and the Rocko Squad: Barney's Best Moments
- "DO SOMETHING!" - Barney and the Rocko Squad: The Best of Barney in Rockoland
- "Hey! I have an idea! Heihachi..." - Barney and the Rocko Squad: A Time of Sharing (Barney)
- "It does feel like that! What fun!" - Barney and the Rocko Squad: The Purple Escape (Min)
Heihachi Mishima is voiced by Jamieson Price (credited as Taylor Henry in Alisa's Adventures in Rockoland) during his visits to Rockoland. Heihachi's voice actor is also Mr. Biggle's voice actor in the classic Kidsongs clips during Barney and the Rocko Squad, as well as Plex's voice actor in the classic Yo Gabba Gabba! clips in the same show, and Roboraptor's voice actor (credited as Taylor Henry) in Xianghua in Rockoland.