Big Body was the largest and physically strongest of the Five Princes, but is quickly defeated by Kinnikuman Super Phoenix. Because of this, he is generally viewed as the weakest of the Five Princes and was not very popular. However, in the anime he puts up more of a fight and from that has gained a slight cult following. Most fans believe that had he fought against Team Kinnikuman instead he would've fared better (though he still would've lost).
He returned to fight Gear Master of the Omega Centauri's Six Spears. He put up a much better showing because he's willing to fight this time around and received his hard-earned victory. When Gear Master got crushed by the hidden chandelier of the Forbidden Palace, Big Body made an attempt to save Gear Master, showing that he cares. He even consoles Gear Master when he passes away,
Kinnikuman Big Body was born in the same hospital as Kinnikuman and the four other contestants, and because of a fire the six children were possibly mixed up so the identity of the true heir to planet Kinniku is left in doubt. Fearing Kinnikuman's power if he manages to ascend the throne, five gods each chose one of the other potential heirs and gave them massive Chojin power as the Five Princes of Fate. Strongman, who was living in Canada, was chosen by the God of Brute Strength (強力の神, Gouriki no Kami) to be his champion as Kinnikuman Big Body.
After Kinnikuman had proven himself worthy to become the next king of his home planet, five evil gods sought out the other potential heirs and gave them great chojin power to become the Five Fated Princes, who all claimed to be the true heir.  Big Body was chosen by the God of Brute Strength.  A tournament is organised to determine who is worthy of ascending the throne.
Kinnikuman is granted a white cape, which must be stained with the blood of his five opponents, and each of these six potential princes - including Kinnikuman - must forge a team of five people to fight to prove their worth.  Big Body is assigned to fight in Aizuwakamatsu Castle, against Super Phoenix in the first round.  He watches as three members of his team lose against Mammothman.  The match between Cannonballer and Mammothman ends in a draw, leading to Big Body stepping into the ring. 
Mammothman threw the match, so that Super Phoenix could fight in his place, and Super Phoenix throws Big Body into the air for an immediate attempt at a Muscle Revenger.  Big Body is caught in the lights above by the force of the throw, before - on his descent - being caught in a Perfect Muscle Revenger.  This knocks him out, as his head collides with a corner-post, and allows Team Phoenix to advance to the next round. 
Big Body is mysteriously shown as still alive, along with all the other Fated Princes, and contacted again by the Evil Gods to help Kinnikuman against the Omega Centauri army during the Omega Centauri's Six Spears Arc.
Kinnikuman Big Body vs. Gear Master
When the Fated Princes show up to kill the Six Spears, Gear Master's opponent is Kinnikuman Big Body. Their match is set to take place in China's Forbidden Palace. While at first Gear Master underestimates Big Body, as he was the first Fated Prince to lose the Scramble for the Throne tournament, he's impressed as Big Body does his best to fight him valiantly. In the end, when the cursed chandelier of the Forbidden City Palace (set to crush the loser and denounce him as a fraud) falls over the defeated Gear Master, with his last words expresses sadness about his own fate, with Big Body there to ease his last moments.
He's finally able to avenge his brutal defeat, valiantly fighting against Gear Master, despite being called a fraud and a loser for all the fight. However, he's found to have embraced some of the ideals of the Kinniku Clan, stopping to console Gear Master in his final moments and loudly claiming that the gods were unjust to him, as he would have forgiven the Six Spears for everything they did in the past as soon as they asked.
When the gods launch their invasion on Earth, Kinnikuman Big Body rushes over to the Mausoleum of the First Qin Emperor. Before he runs over there, he blames the God of Strength for causing the gods to come after him.
The God of Harmony makes an announcement. He knows that Kinnikuman Big Body is the chosen one for the God of Strength and that he's fearless, since he's fighting the gods themselves. Upon Big Body calling him the leader of the Gods, the God of Harmony corrects him, revealing the gods are all equal. Even the God of Strength is the same like them.
Big Body is insulted by the comparison and stands up for the God of Strength even if he belongs to the Evil Gods. Even if he's evil, at least the God of Strength doesn't advocate for genocide on the Chojin race. He warned Kinnikuman Big Body about the God of Harmony's faction in time.
Kinnikuman Big Body is clueless about good and evil in this world and thinks it's all too complicated for a guy like him. The God of Harmony thinks that the will of the gods are beyond the understanding of mere mortals. And because of that, the gods are going to make the mortals understand. Chojin are no longer needed by the gods on the mortal plane.
Big Body retorts that he could decide that the gods' jobs are done and that the mortals don't need them hanging around. One of the gods is insulted by this, but the God of Harmony gestures at them and tells them to stand down. The God of Harmony says that the Chojin have convinced the former God of Mercy to stand down from his role of maintaining the world to them. But the God of Harmony says they aren't worthy enough for that, and thus he and the other gods have started the final judgement of the Chojin race.
The God of Harmony argues against The Man and gives his take on the current situation. To the God of Harmony, it's more likely that Chojin are no longer needed by this world. Because of their conflicting viewpoints, the coexistence of Chojin and the Gods are impossible. According to the God of Harmony's companion, the Gods have became Choushin, super gods, and want to claim this plane as their own. And they have the conviction to make that dream possible.
The companion takes off their cloak and reveals himself as the God of Commandments, but the God of Commandments says his new physical body must be called Rampageman. Rampageman points out that their current location is a fitting place for Kinnikuman Big Body to die after a history lesson of the Mausoleum. Rampageman wants Big Body to not hold back against him. As Big Body charges at Rampageman, his wounds induced by Gear Master act up and cause him to stall. Despite these wounds, Big Body will not back down.
Just as Big Body charges at Rampageman again, Pinchman, Golemman and Cannonballer reveal themselves and confront Rampageman. The trio will not let Rampageman hurt their captain. Cannonballer starts off strong with a Cannon Lariat, but Rampageman stops it and throws Cannonballer aside, calling him pathetic. Pinchman moves in with a Pinch Claw, hoping to avenge Cannonballer's loss. Rampageman stops the Pinch Claw in its tracks and bends Pinchman's pincers with no effort. He then impales Pinchman with a Punishment Engraver straight from his chest.
Golemman tackles Rampageman with a Golem Spear. Rampageman kicks him aside, but Golemman catches Rampageman by his legs and follows up with a Golem Giant Swing. Just as Big Body cheers on Golemman, Rampageman breaks free and elbows Golemman in the chest. After Big Body's futile effort at ordering Golemman to run away, Rampageman finishes off Golemman with a Cathedral Bomber.
Disappointed by how easily he defeated them, Rampageman notes that they may not need the Capillaria Rays to wipe out the Chojin race. Rampageman demands that Big Body give him the God of Strength's piece. Big Body tries to play dumb, but Rampageman reveals his piece of the crystal to in an attempt at calling out his bluff. The ploy has loosened Big Body's lips. In an attempt at gathering more info, Rampageman reveals a secret arena in the Mausoleum.
As the God of Strength was Rampageman's former friend, he wants to know why he chose Big Body. And to do that, Rampageman will fight Big Body. All Chojin will keep their promises in the ring, right? Just as Big Body is about to enter the arena, Leopardon steps in and fights Rampageman.
Despite his "humiliating defeat" to Mammothman, Leopardon decides to step in the ring for Big Body. Leopardon's loss to Mammothman has tarnished the image of Kinnikuman Big Body's team. Leopardon has never forgiven his defeat ever since that day. Just before he fights Rampageman, Leopardon begs his leader to give him the signal and Big Body complies. Rampageman observes that Leopardon is a weirdo and asks Big Body to step in the ring.
- Big Body begins by doing 3 poses that show off his physique while also hitting the opponent with his elbows, the final blow sends them in the air. Big Body leaps in the air and catches the opponent on his shoulder, back first and performs 6-7 forward rolls. He finishes by driving the opponent into the floor with a sit-out power-bomb.
Maple Leaf Clutch
- Big Body throws the opponent against the ropes, as they rebound he punches them full force back into the ropes again. This time after the rebound he catches them and forces them into an arm-breaker. Big Body then puts them on his shoulders and leaps into the air where he drapes them behind him. From this position he squeezes their head with his calves while grabbing an arm in each of his hands and dropping them head first into the floor. The end result resembles the Canadian Maple Leaf hence the moves name.
- Big body grabs his opponents legs and begins to swing them round, this lifts both Big Body and the opponent into the air where he releases their legs and they fly into the canvas full force.
Dragon Sleeper Backbreaker
- Big Body grabs the opponents head from behind bending them backwards. He then lifts them up vertically and drops them back on his knee.
Back 2 Backbreaker
- Big Body lifts the opponent up across his back facing away from him and then bends forward pulling opponents head and legs forward too. This bends the back of the opponent very painfully.
Big Body Tackle
- Big Body charges down the opponent and puts all his weight behind a bone crunching tackle.
Super Strength Atomic Bomb
- Done as a counter to Gear Master's Muscle Revenger. Big Body counters the headbutt with a claw hold. He swings his opponent around and lands an atomic bomb grapple on them.
Super Strength Exploder Suplex
- Big Body grabs his opponent and places them into an explosive suplex.
Super Strength Jet Tornado
- Big Body spins around and around in a tornado, kicking up any dust particles in the area. Used in his match against Gear Master.
- Team Big Body: Commander
- Planet Kinniku Throne Successor Candidate
- Win/Loss Record (Singles)