The younger brother of Tatsunori Kinniku.
The younger brother of Tatsunori Kinniku, Sadaharu Kinniku started out life into the royal Kinniku family. He possessed a genius wrestling ability and believed himself to be superior to his brother. At the mere age of thirteen, he unconsciously performed the Muscle Spark, which killed his sparring partner in the process.
He was thus locked away in an underground dungeon and his existence erased from history. After receiving the death sentence, he escaped from prison to Mt. St. Parfait where he faced off against Mirageman. Recognising Sadaharu as the descendant of Silverman, Mirageman invited him to become reborn as the Perfect Chojin Nemesis.
Nemesis was born into the Kinniku Clan, where he was taught all about wrestling and chojin culture, but - as the younger brother - his older brother was destined for the throne.  He was great friends with his brother, but still the people around him spread rumours and lies, in which they insisted he was a danger to the people. He mastered the Muscle Spark at the age of thirteen, and his skills far outstretched those of his older brother. 
Fearing his power, which resulted in the death of his opponent, the people of Planet Kinniku imprisoned him beneath the Kinniku Temple. They proceeded to wipe all mention of him from history, so his name was forgotten.  At some point during his imprisonment, he is visited by two children: Harabote Muscle and Mayumi Kinniku.  He explains that - were he not imprisoned - his presence above could spark civil war, but that he loves his brother and believes Tatsunori Kinniku will be a good king. 
Nemesis' brother - Tatsunori Kinniku - visits him in the dungeons, but one day tells him that he is to be executed within ten days.  He proceeds to escape the dungeons and heads to Mont Saint Parfait, where inside he is confronted by Mirageman.  After a series of blows, Nemesis defends against Mirageman with the Kinniku Curtain.  Mirageman proceeds to tell him the Kinniku Clan history, before allowing him to be reborn as a Perfect Chojin.  At some point during these events, he watches from the Chojin Graveyard the events on the surface world involving Tatsunori. 
He witnessed the officials and bureaucrats of Planet Kinniku try to assassinate Tatsunori, and for three days he withstood their torture and betrayal with his Muscle Curtain.  It is this experience that motivates him to return to Earth and destroy the Kinniku Clan, as he sees corruption everywhere and seeks to purify Planet Kinniku by eradicating any potential cause for infighting and civil war. 
After the end of the first-stage of the tournament, a new waves of Perfect Chojin arrive to begin a second-stage of the tournament.  They are introduced as the New Perfect Large Numbers, with Nemesis as their leader.  Nemesis demands that Peek-a-Boo end his life, according to Perfect Chojin ideals, but - as he goes to attack Peek-a-Boo - Peek-a-Boo takes him into a Kinniku Buster.
Nemesis counters him with a Muscle Spark, but Kinnikuman uses his body to soften the blow and save Peek-a-Boo.  Later, Nemesis and Polarman take The Machineguns and use a Busters Docking on them.  Nemesis goes on to reveal a seven step pyramid, where the second-stage of the tournament will take place.  The New Perfect Large Numbers form into the shape of a gun, before they take their places on the steps of the pyramid, and Nemesis takes the sixth step. 
Nemesis vs. Robin Mask
A series of tunnels leads the Justice and Devil Chojin to their opponents: Robin Mask - on ring six - is assigned Nemesis.  Nemesis starts with an upper-hand, as he employs a one-handed back-breaker.  Robin eventually is able to land a knee-kick.  After exchanging a series of blows, throughout the other matches, Nemesis attacks with a Flying Head Scissors.  Robin Mask evades and counters with a Boston Crab.
Nemesis evades the attack and reverses it with a Pile-Driver, but Robin Mask breaks free in turn with a headbutt, and proceeds with an Ice Rock Gyro. They engage in a series of blows, before both fall to the canvas and hold each other in an equal grapple.  At this point, Nemesis reveals the origin of the Perfect Chojin.  He states that Perfect Chojin are descended from chojin chosen by the gods, but all other chojin are descended from those rejected by the gods. He proceeds to use a Nemesis Driver. 
He drives Robin's head into the canvas, but Robin pulls himself out.  Nemesis throws Robin again with a double-arm suplex, and follows through with a high-kick, until Robin is able to counter with a throw. Robin uses a Unicorn Fire Head, but Nemesis counters after with a Battleship Sinker, and Robin still stands, as he reveals that Kinnikuman is his main motivation and reason for throwing away his pride.  He describes in detail how his defeat by Kinnikuman allowed him to be reborn as a better chojin with Friendship Power. 
Nemesis knocks off Robin's Analo Staff with a knee-strike, and they engage in a series of blows again.  He is eventually able to stop Robin's blows with the Perfect Defender, which is a variation of the Muscle Curtain, and continues to use the Perfect Assailant, which Robin dodges and uses to lead into a Robin Special.  Nemesis breaks free and uses a Scorpion Death-Lock. He convinces Robin to remove his armour and fight at full-power, which leads to Robin attempting a Naked Tower Bridge. 
The attack starts to tear apart Nemesis' body, but also has an effect on Robin's body.  Nemesis eventually breaks free and uses a Tombstone Driver, leading Robin to try a British Steel Edge. The technique is broken, leading Robin to say goodbye to his friends, before Nemesis uses another Battleship Sinker.  Robin is knocked out and the match it declared to be in Nemesis' favour.  Nemesis then tosses Robin's body down the pyramid and into the sands of the dunes below. Despite Kinnikuman's attempts to save Robin, he is only able to save the visor of his mask, and Robin's body sinks out of reach of his friends. 
After Polarman loses to Warsman, Nemesis enters the ring.  He takes Polarman into a hold, and tries to make Polarman stab himself with his own hand, so that he will die according to the ideals of the Perfect Chojin, but Warsman blocks the blow with his hand. Warsman and Nemesis then grapple. He tosses Warsman aside, before finally killing Polarman with Polarman's own hand.  Nemesis then throws Polarman's body into the sand dunes, where it is sucked away alongside Robin Mask's body. 
Nemesis reveals to Warsman that he is effectively immortal, as a member of the Perfect Large Numbers. He states that the Perfect Large Numbers have descended to judge the rest of chojin kind, as they fear they will lead a brutal path of the ancient chojin, and to eradicate those too powerful. It is then shown the Gold Mask has been stolen from Planet Kinniku. Nemesis states that Kinnikuman is the cause of such issues. 
Buffaloman reveals that a second group of Devil Chojin, much like the second group of Perfect Large Numbers, have descended to attack the 'bosses' of the Perfect Chojin, with the intent to defeat Chojin Enma.  Nemesis explains that Chojin Enma is "The Man" and the founder of Perfect Chojin. He continues to state that the Fire of Inner Strength and Friendship Power are one in the same, and this Friendship Power is spreading around regular chojin and making it so their power could exceed the gods. To prevent ancient history repeating itself, the Kinniku Clan and all their allies must be eradicated. 
Nemesis arrives at the Chojin Graveyard, after having left the pyramid.  He seeks Chojin Enma, only to find General Devil, and reveals he is a descendant of the Kinniku Clan.  General Devil plans to collect all ten dumbbells of the Origin, so that he may eradicate all chojin from existence, including himself.  Nemesis attacks General Devil, but - as he is not one of the ten Origin - General Devil counters the attack and refuses to fight him.  General Devil leaves and Nemesis follows him to National Stadium. 
Nemesis vs. Ramenman
A new stage to the tournament is announced, and Nemesis enters the second ring of the Yggdrasil.  Nemesis' next opponent is set to be Ramenman, who begins the match with a low assault and a spin kick, which Nemesis evades.  He uses a right-arm lock on Ramenman, before forcing him on the ground, and Nemesis reveals publicly that he was one a member of the Kinniku Clan. Ramenman breaks free with a Huricanrana and a jumping kick.  Ramenman follows with a Spinning Dragon Tail-Kick. 
Ramenman states his intention to teach Nemesis how the power of a Justice Chojin can trump the power of hatred, as part of his gratitude to the Kinniku Clan that helped redeem him.  Nemesis attacks with a tackle, but Ramenman counters with a knee-kick and enzurigiri, and - when Ramenman goes to attack with chops - Nemesis counters with a Muscle Curtain and a low kick, before attempting a front suplex. Ramenman breaks free and they both dive at one another, only for Ramenman to dodge at the last second. 
He attempts a Camel Clutch on Nemesis.  The flexibility of Nemesis allows him to bend further back, escaping the hold with just his feet, and he retaliates with a Nemesis Driver. He throws Ramenman towards the corner-post, but Ramenman remains standing (despite bleeding profusely from his forehead). Nemesis tackles him to the ground and unleashes a series of blows, before taking him in a back sleeper-hold. This is followed by an Ultimate Romero Special. Ramenman digs his fingers into his old head scar, which causes blood to spurt out and splash upon Nemesis' face. He then stomps on Nemesis. 
Nemesis throws Ramenman to the side.  Ramenman endures a series of blows, despite summoning forth his Friendship Power, and Nemesis continues on with a Battleship Sinker.  The face of Ramenman transforms into Mongolman, and is able to break the attack with a Leg Lariat. Ramenman seems to gain the upper hand, as he moves into a Kowloon Wall Drop.  Nemesis takes the attack, but survives and continues with a Tombstone Piledriver.  The dramatic turnaround causes Ramenman to help Nemesis realise that he has used Friendship Power, much like the Justice Chojin.
This angers Nemesis enough to attack an already defeated Ramenman, and - to prove that he is not a Justice Chojin - proceeds to use a Muscle Spark on Ramenman.  This results in Ramenman's defeat.  On seeing that Ramenman miraculously survived, Nemesis tosses him outside of Yggdrasil, and Ramenman is caught by Kinnikuman, where he reveals that Kinnikuman and Nemesis' Muscle Sparks are different, before he is taken away on a stretcher to the hospital. 
Nemesis vs. Kinnikuman
Nemesis wishes to immediately fight, but is ordered by Chojin Enma and Harabote Muscle to rest.  He dives through the roots of Yggdrasil, along with Kinnikuman and others, and they are taken to Koshien Stadium.  The match is declared to take place the following day at 12pm.  Kinnikuman and Nemesis enter medical suspension for the evening, in order to recover from their injuries. 
They arrive at the ring the following day, with Nemesis enters the red corner of the ring with an old cape of the Kinniku Clan.  He announces that he has forgone a second.  The two start with a grapple, until Kinnikuman counters with a Full Nelson and a Dragon Suplex.  Nemesis breaks free and they grapple again, until Nemesis uses a Pile-Driver, after which he gains the upper hand and delivers a series of blows. He manages to knock Kinnikuman to the canvas, despite it being the start of the match. 
Kinnikuman then uses the Muscle Curtain.  This leads Kinnikuman to believe he has an advantage, but Nemesis raises the guard to his mask and uses the Muscle Curtain in turn. Each time Kinnikuman attempts a counter, Nemesis breaks them with his own counter-attack. Nemesis continues with a Perfect Assailant, which Kinnikuman evades before using a Chojin Hanging.  Nemesis breaks the attack with a headlock. 
He strikes Kinnikuman to the mat with a modified Bulldog Headlock, before concussing Kinnikuman with a back-drop and following with a Scorpion Death-Lock. Kinnikuman attempts a Kinniku Buster, but Nemesis reverses the technique with a Perfection Buster.  This begins a countdown.  Nemesis drags Kinnikuman upright, despite being still unconscious, and ends the countdown. He slaps Kinnikuman awake, at which point Mayumi Kinniku arrives and reveals Nemesis true name is Kinniku Sadaharu. 
Mayumi explains of the time when he once met Nemesis as a child, and that Nemesis is what inspired him to become a good king and that he believes Nemesis has a good heart. Nemesis states that he may have wished the Kinniku Clan to prosper then, but has since changed his mind.  Nemesis proceeds to state that the invention of the Muscle Curtain is what caused him to wish the Kinniku Clan eradicated.  He then offers Kinnikuman and Mayumi a chance to join him as Perfect Chojin. 
They refused, as Kinnikuman states that the Kinniku Clan is not the problem, but Nemesis lack of faith in them is the real problem.  Nemesis rushes at him with a series of punches in retaliation. Kinnikuman manages to suplex Nemesis, before using Robin Tactic No. 1, and ends with a back-drop. Nemesis sets up for his Nemesis Driver.  Kinnikuman - inspired by the support of his friends - breaks the technique, before using a Kinniku Driver.  Nemesis manages to stand, despite his injuries, and Mayumi invites him back into the Kinniku Clan, the way that Nemesis invited him to become a Perfect Chojin.
Despite his actions towards Peek-a-Boo earlier within the arc, Peek-a-Boo appears to support Nemesis and act as his second within the match, and Neptuneman appears to also offer his support.  Nemesis states that he will accept the views of the Justice Chojin if he loses, but that Kinnikuman must become a Perfect Chojin if Nemesis wins.  They exchange a series of blows and various techniques.
Kinnikuman hears the spirit of Robin Mask, which inspires him to survive the Battleship Sinker by grabbing onto a rope at the last second.  In exhaustion, both Nemesis and Kinnikuman collapse.  They both stand, while the crowd cheers evenly for both, and they both engage in a series of blows, as they strive to get in the final finishing move on the other. Nemesis attempts Silverman's secret technique: the Arrogant Spark.  This seemingly knocks out Kinnikuman, but Nemesis' armour cracks and he is downed. 
Kinnikuman proceeds to use a Muscle Spark on a severely weakened Nemesis, and uses his Fire of Inner Strength.  This downs Nemesis, who - as the countdown begins - sees the spirit of Tatsunori.  He proceeds to lose by a knockout at 64 minutes and 28 seconds. It is revealed that Nemesis realised he lost at an earlier point, but continued to stand - and force Kinnikuman to attack - in order to test Kinnikuman's resolve.  Kinnikuman offers him again to rejoin the Kinniku Clan, but Nemesis refuses. 
Nemesis states that he intends to kill himself with a sharp implement, but it falls from his hands, as his hands have been damaged due to the Muscle Spark.  When Chojin Enma arrives to take Nemesis' life instead, Neptuneman appears and states that the rule (regarding suicide on defeat) should be eradicated, and challenges Chojin Enma to a fight on Nemesis' behalf.  General Devil takes Neptuneman's place, leading Nemesis' fate to be decided at a later time. 
Nemesis goes with Peek-a-Boo and Neptuneman to Ayers Rock, where General Devil and Chojin Enma are due to do battle.  At the end of the match, Chojin Enma is defeated and Nemesis helps him to stand.  They decide that they will give up their cause to eradicate all chojin, as per the conditions set by General Devil, but they will return if the chojin ever become a threat to the rest of existence. They make peace with one another, and Nemesis fist-bumps Kinnikuman, as the two become allies. 
- One of Nemesis's finisher. Nemesis tosses his opponent up into the air. Then he faces back-to-back to his enemy and grab the opponent behind his back then slam the opponent's head into the ground. It was first uses twice to kill Robin and fight with Ramenman, but in the battle with Kinnikuman, Suguru manages to grab the rope to minimise the damage.
New Kinniku Buster
Perfect Muscle Spark
- One of the Kinniku Clan's Three Great Techniques. Nemesis bounces his opponent off his chest and into the air numerous times. He then leaps up after them and gets behind them. He then grabs their wrists with his hands, their neck with his right leg, and their left leg with his left leg, and pulls. As they descend, he gets back-to-back with his opponent and grabs their arms and hooks their legs with his. Right before they hit the canvas, he arches his back causing his opponent's body to fold, and drives them neck and knees first into the canvas. Despite being an extremely difficult technique to pull off, Nemesis was able to use it when he was only thirteen.
- Despite looking identical to Suguru's Muscle Spark, most people claim it is a different technique since Nemesis's Muscle Spark always carry a intent to kill (since Muscle Spark is a mercy move to let the opponent live)
- A technique look quite similar to Kinnikuman's Kinniku Driver, but more effective and difficult(This technique demand a extremely flexible body to perform, which only Nemesis can since he can coil himself around the opponent's neck just by break some ribs to make his spine more flexible). Nemesis first drop kick the opponent and push them into the air. While descending on the air, Nemesis grabs both the opponent's leg while step both his feet on the opponent's chin. Since he keep both his legs on the chin, it is near-impossible to pry him off. But in the battle with Kinnikuman, Suguru was able to counter this technique by rapidly spinning around to make Nemesis lose his balance and escape.
- The basis for the Niku Curtain. A special defensive stance that enables the user to stand up to an onslaught of attacks. Nemesis holds his forearms in front of his face in an upside down V. But this technique is uses to defend from attacks, it can't protect the user from grappling technique or an attack from above the guard.
- Nemesis jumps into the air and proceed to ascent to a nosedive. Then he clasped his hand and stab the opponent. He first uses this technique when he throws Robin Mask into the air and stab his back with it. Later, he uses it again in the battle with Kinnikuman
Neck Pump Up
- Nemesis takes a deep breath in order to make his neck swell up in order to make a gap to escape. This is an effective move to escape from any grappling technique that grab his neck. He uses this technique to escape from Robin Mask's Robin Special.
Ultimate Romero Special
- A modified version of Romero Special. Instead of grabs the opponent's arms and locks them, Nemesis first put the opponent on a back choke sleeper hold then locking his legs with his opponent's then elevating them up into submission .
- A better version of Kinniku Buster Reversal, when Kinnikuman uses Kinniku Buster on him. Nemesis not only reverse their positions so he is the one who has Suguru trapped in the Kinniku Buster, but he also lock all of his limbs by using his legs to hold Suguru's arm to prevent him from using escape technique such as Neo Kinniku Buster.
- The prototype of the Muscle Spark. Nemesis bounces his opponent off his chest and into the air numerous times. He then leaps up after them and gets behind them. He then grabs their wrists with his hands(his right arm grabs his opponent's left arm and his left arm grabs his opponent's right arm then entangles it behind his opponent's head), their neck with his right leg, and their left leg with his left leg, and pulls. As they descend, he gets back-to-back with his opponent and grabs their arms and fold it tightly and hooks their legs with his. This cause the opponent's head begin to look down to the ground to the speed pushing. Due to never practising it for his life, the Arrogant Spark puts a lot of strain on Nemesis's body, making it unable to kill Kinnikuman and damage his body even worse than Suguru
- A two platoon manoeuvre perform by Nemesis and Polarman. First Nemesis and Polarman lifts both their opponent into the air. Then in the air, Nemesis places half of both the opponent's neck and one of their shoulder on his shoulder and grabs one of their thighs while Polarman do the similar set-up to both opponent, creating a twin Kinniku Buster. Their then jumps up and lands in a sit-down position, causing damage to the neck, spine, and groin. It was first use on Kinnikuman and Terryman, but it was interrupted by Diabolos's Spring Bazooka.
- Win/Loss Record (Singles)
- O Robin Mask (Battleship Sink)
- O Ramenman (Perfect Muscle Spark)
- X Kinnikuman (Perfect Muscle Spark) (64 minutes, 28 seconds)
- Nemesis is named after Sadaharu Oh.
|Strong the Budo|
|Perfect Large Numbers|
|Max Radial, Turboman, Crushman, Dalmatiman, Marlinman , Peek-a-Boo|
|New Perfect Large Numbers|
|Marvellous, Jak Chi, Nemesis, Polarman|
|Mirageman, Abyssman, Painman, Psychoman, Ganman, Thingman, Crowman, Justiceman, Goldman, Silverman, The Man|
|Qilinman, Screw Kid, Kendaman, Neptuneman, Big the Budo, Omegaman Dexia, Mammothman, Seiuchin|