Ikemen Muscle (イケメン・マッスル) is Harabote's son. He takes over his position as chairman of the Choujin Olympics. He is not related to the Kinniku family. He is ridiculed about his face, and initially greatly dislikes Mantaro just like his father hated Suguru. He is very fond of money and constantly seeks to make a profit. Later, he develops a friendship with Mantaro.
Ikemen is the son of Harabote Muscle and the brother of Jacqueline Muscle. He replaces his father as the chairman of the Chojin Olympics, where he becomes a strong supporting character for several of the arcs onward. He is initially an antagonist of Mantaro Kinniku, working to subvert his successes and covertly seeking to find people that can defeat him. In the manga, he shows mild preferences to other wrestlers.
He develops many of the preliminary tests for the Chojin Olympics Resurrection, while often announcing matches and results, and goes on to appear in every arc afterwards, albeit as a background character in some. Ikemen's main appearances are in the Chojin Olympic Resurrection Arc and the Ultimate Chojin Tag Tournament. He often provides exposition and support for various characters. Later, Ikemen becomes an ally and joins Mantaro in working towards justice.
Ikemen claims to pride himself on fairness, but often says things contrary to this belief such as 'you can't stop evil with fair play any more'.  He is also regularly seen attempting to undermine Mantaro and bring about his defeat.  He expresses a sadism similar to Jacqueline Muscle and Kevin Mask, in that he explicitly states that one must fight violence with violence in order to overcome evil forces. He does - however - lack their bloodlust and is visibly repelled and disgusted by overt violence, to the extent that Jacqueline scares him in her earlier chapters. 
He is overall a lot calmer than his father and sister, but is still very expressive and emotive in his reactions when overcome with strong emotions. He is a shrewd businessman and was able to take the bankrupt Intergalactic Wrestling Federation and bring it back to glory, and he is also inventive in his money-making schemes (although unethical), such as trying to gamble in the past to provide an income with guaranteed wins. He also claims to loathe cowardice, but has tendencies to cowardice.
He is often used as comic relief, but is respected by his family. Harabote often defers to Ikemen and trusts his judgement as the new chairman, while Jacqueline refers to her brother with the honorific 'sama', which denotes a great deal of trust and respect. He holds some insecurity in not being alike Jacqueline, as he was teased and bullied for his differences by other children.  It is revealed Jacqueline used to wrestle and torment him as a child, although it may have been in jest on her part.  Jacqueline also stole his cherished possessions as a child, to which he still bears a grudge.  He fears she will steal the chairman position.  Ikemen is prone to mistakes when nervous, such as his “Freudian slip” when Jacqueline upsets him and he mistakes ‘corner’ for ‘commoner’. 
Ikemen makes his first appearance during this arc, as the son of Harabote Muscle, and is announced as his successor as chairman of the Chojin Olympics.  He often appears alongside his father, both showing exuberant and energetic personalities, particularly in their attempts to have Mantaro's team defeated and humiliated by his competitors. He is often the character to make announcements and supervise matches. He is later revealed to be Jacqueline's brother. 
Early in the arc, we see Ikemen scout The Nosonman and secure him a place in the Japanese preliminary matches for a place in the Chojin Crown . He believes in Nosonman's "hunger to win". He is shown to be an optimistic personality, averse to cowardice and in awe of determined personalities. On Mantaro's defeat of Nosonman, he feigns civility and follows by forcing on him an Octopus Hold, which he passes off as something done in his excitement, as he wishes Mantaro good luck and delivers unto him his pass for the following games.  It is worth nothing - like Jacqueline - he has a sadistic side; when Kinniku Mantaro catches on fire, he says to "let [him] burn". 
Ikemen acts again as commentator and announcer . He rides in a helicopter to watch one of the races, which will determine who makes it into the finals, and - in his frustration - actually causes the pilot to crash, which has the knock-on effect of sending Kinniku Mantaro soaring and flying from the log he struggles to cross, and this allows Mantaro to make progress. Ikemen damages his helicopter during this incident, which he laments will be money spent out of his own pocket. 
He is prone to subtly subverting the rules via loopholes, such as in volume sixteen where he decides against disqualifying Kevin Mask by claiming he never finished his sentence (although the real reason was a personal interest in Kevin and the potential profit from his battle).  He is shown to care about his father's opinion, hiding the facts of the battle from him, such as Kevin's disadvantage, and often speaks out of turn, forgetting that he is in a public place, such as nearly revealing he cares primarily about profit.  He shows dedication to his position by leaving a first-class plane to spend time with the B Block contestants, so that he does not favour one block over another by spending more time with one than the other. 
Ikemen reveals he was bullied in his youth, before the Destruction match.  He shows attraction to a flamboyant female and momentarily bonds with Mantaro Kinniku, as he attempts to get a date with the young woman, and shows obvious signs of arousal along with Mantaro Kinniku. 
Ikemen – in his jealousy of Jacqueline – manages to tear his trousers and embarrass himself on stage, furthering his negative feelings to his sister, as he attempted a stunt to steal back attention.  He is later called ‘ugly’ by his father, further hurting his emotions.  He later fears being forced to resign, as Ricardo is revealed to be a member of the DMP. Jacqueline later speaks ‘for’ him when he is indecisive in his decision against a potentially illegal move made by Ricardo against Jade. 
Ikemen reveals that Jacqueline “twisted [his] arm” into creating the Punishment X Ring, as featured in the Ricardo vs. Mantaro Kinniku match, and both he and his father express fear of her attitude. He experiences a few moments of comedic relief, such as when Jacqueline steals the bell from him in his excitement to ring the start of the match, but otherwise takes a very small role compared to his sister. Jacqueline chides him for thinking of profits more than the rules, while later Ikemen shows pride that she realises the error of her ways in preferring bloody battles to the emotional stakes behind each match. He shows distaste when Harabote observes she would be a better successor as chairman, which is his last appearance in this arc.
Ikemen appears alongside Jacqueline and her “Army of Idols”, as named in the English translation. He declares that Meat’s absence is a threat to the entire Justice Federation, and declares they will use their full resources to help rescue him from the current threat. The Justice Federation’s “Airship Vision” arrives to allow them to see events elsewhere. Together, they watch the Hanzo vs. The Puppet match. He is mostly a background character during the very start of this arc, although he can be seen cheering on Hanzo and reacting with horror to his injuries. He continues to ring the bell for matches, as he has done in the previous arc. 
He can be seen offering some knowledge to the watching crowds, during the Tattooman and Barriefreeman match, as he reveals he is an avid doll collector. He also provides momentary comic relief, as he and Mantaro both release some mucus on seeing mucus during the match, much to the disgust of Rinko and others.  Ikemen follows Jacqueline and Rinko in their pursuit of Mantaro, as he seeks for the next match, and can later be seen recoiling in horror during the Blood Evolution vs. Demolition match, as his chojin status allows him to sense great danger. He goes on to tackle Mantaro in his desire to reach Meat, saving his life while he is still in recovery and preventing him from being injured. 
Ikemen clings to Jacqueline in fear at the mention of spirits.  He expresses confusion and horror at the idea that Mantaro and Kevin would not think of the long-term consequences to their actions, to which Rinko replies that those same qualities give her hope, as it shows they will do anything to save their friends.  He is mistaken as a ghost later on by a secondary character, which causes him to break down and state he "can't help the way [he] was born".  When Asuraman - in a later match - slices off his own leg, Ikemen shows signs of nausea and faints. He also throws items at the big screen in support of Mantaro, during the Mantaro vs. Asuraman battle. He is otherwise seen very little in this arc, aside from cheering on the Seigi Chojin. 
Ikemen appears with Jacqueline on stage, in formal-wear, as Harabote presents awards to the Seigi Chojin for their achievements over the past few arcs. Ikemen hands the MVP award to Kevin, only for it to fall through Kevin's hands, and for Kevin to be incapacitated due to time distortions.  Ikemen calls for a doctor.
He next appears in a theatre, where he listens to a speech delivered by Meat on the nature of time-travel. He sits front-row of a small group of Chojin.  He is later seen with Rinko, Harabote, Meat, Jacqueline, Keiko, and Tomaki, watching the attempts to create the ship on a small television in a meeting room. They discuss recent events, providing some exposition.  They celebrate together on completion of the ship. Ikemen is forced to travel alongside Jacqueline, despite his protests. Ikemen is given a special seat behind team-leader Terry. 
After take-off, Ikemen retreats into a secret room he had built on the ship. It is filled with luxury. Jacqueline becomes suspicious of his now apparent excitement in travel and change of heart, and finds his gambling magazines and discovers he plans on making ‘sure’ bets in the past to make profit, and she proceeds to criticise him on his selfishness. They then leave to find Rinko as a stowaway in the luggage bay. 
Ikemen is left to pilot the ship with Rinko and Jacqueline, after the Time Warp Eight abandon ship to save Robin Mask. Jacqueline leaves with Rinko in the two escape pods, leaving Ikemen to walk down the mountain with their luggage instead.  Ikemen however he also helps to save Alisa's life - and Kevin's by extension - by realising what has happened and calling for an ambulance (due to the lack of phone signals in the past era, only Ikemen could have made that vital call). Ikemen worries about funds, due to unexpected time spent in the newly announced tournament, and decides to leave Kevin unattended to make bets, which will provide money for the duration of their stay in 1983. He announces his primary intent is selfless, but also lets slip he has some selfish desires for profit and that he’s glad to be free. He hears a noise in the luggage bay, but chooses to ignore it as part of his imagination.  Unable to use his money from the future to make bets, he obtains a seat for the Tag Tournament and watches from the crowds. 
This leads to his absence from the Kevin Time Ship, which allows for Kevin to be kidnapped by the Time Chojin. Ikemen notices that Jacqueline has seen him in the arena, once Kevin is presented at the side of the stage in his life-support machine, and so he takes a disguise as a beer seller in hopes of avoiding her ire. 
Ikemen reappears in Mantaro's changing room, where he is recuperating, and is heavily chastised by Jacqueline for allowing Kevin to be kidnapped, as he gave into seemingly selfish desires to make money by gambling in the past. After he assures her his motives are selfless, and that he plans to don the costume of Kinnikuman Great III, so that Mantaro will not be disqualified, Jacqueline shows him great respect and gratitude for his sacrifice. He thus acts as a substitute for Chaos . In the following match-ups, Harabote and Mayumi comment on the drastic change of appearance, to which Mantaro makes excuses and some comedic relief ensues. The two get frozen like M.U.S.C.L.E figures and placed into plastic balls, which enter a vending machine to determine who falls where to get which match-ups. 
Chaos returns and steals his mask from Ikemen, then kicks him off stage.  Ikemen lands on top of Harabote, creating some issues with Harabote as judge and chairman, and so - distracting them - he changes back into his civilian attire. 
He socialises with Jacqueline, Meat and Rinko over a meal, and he also searches with them for Mantaro and Chaos when their whereabouts are unknown. Later, after a disagreement, Rinko picks his pocket and uses the money to pay for their meal much to his horror, albeit he immediately calms down and his show of emotion was a fleeting one.  Later, during the Hell Carpenters vs. Muscle Brothers Nouveau match, he can be seen motivating Chaos/Great - through words alone - to fight in battle to save Mantaro's life. He compliments Great's ingenuity and also celebrates his success in battle, before he provides support for an injured Mantaro. 
He provides invaluable emotional support to Rinko, as well as participates in domestic activities in the orphanage and sleeps there alongside Jacqueline, and he has a long scene with Rinko in which he prevents her from changing the past by divulging the truth to Mari of their relationship; through this discussion, Chaos recognises his similarities to Rinko and feels less alone . He observes the final matches along with Rinko and Jacqueline, and later returns on the time-ship to his natural time period. It is unknown what happens to him after this point, due to this being the finale of the series.
(More to Come)
Ikemen's appearance in this arc is brief.
He announces that they are about to reveal the match-ups, presumably in the form of the Pachinko machine (pinball in the dub), but six masked men - in disguise as Mantaro Kinniku - swarm the stage. They appear on bicycles and state a grievance with the current Wrestling Federation, and Dazzle takes it upon himself to attack Ikemen when Ikemen protests to the interruption. Ikemen is subsequently thrown from the Stadium at some distance, where Harabote follows after him in concern. He is not seen in this arc again.
Ultimate Muscle: Changes
It is worth noting a substantial change of characterisation between anime and manga, perhaps due to the American commission by 4Kids (with 4Kids notorious for 'Americanising' anime, including heavy censorship and plot changes). Just before the battle match-ups, Ikemen "accidentally" forgets to mail the invitation to Mantaro in a blatant act of sabotage, which - compared to his manga self - is a very unfair and biased act from a man that typically prides himself on fairness. He goes a step further in the anime, by using his pachinko machine to attack Mantaro and cheat, which is rather different from his manga counterpart that - despite his desire to see Mantaro defeated - still abides to the rules and does not discriminate between Siegi Chojin . 
There are further various changes in the anime, particularly the English dub, as his negative traits become exaggerated. He expresses some transphobia in the English dub in specific, in regards to the Pri-Clun match.  He also exits his plane for selfish reasons in the anime, as opposed to spending equal time with each team, and specified "dirty deeds, mind games" as some of his reasons. He is also rendered as comic relief and the designated villain of this arc. Indeed, he is heavily injured as Jacqueline drives a plane through his parachute and sends him hurtling to the ground. He is also seen to intensely dislike Jacqueline, as opposed to having more conflicted feelings towards her and a grudging respect. 
- Ikemen Muscle was renamed to Ikemen McMadd in the dub of the anime and translation of the manga, which was done to eliminate confusion (due to the Muscle family bearing the same name) and as a lighthearted parody of wrestling legend Vince McMahon
- Ikemen is an avid doll collector with a vast knowledge of dolls 
- Single - much to his consternation
- Enjoys karaoke 
- The mastermind of many of the games and challenges in Nisei's Chojin arc
- He enjoys vanilla ice and is seen to enjoy wine, sake, and hot crab
- Ikemen is seen to be bald in the recent era, with his blond locks being a wig 
- Shows a mild fear of ghosts 
- Is considered 'heavy', as Seiuchin and Gazelleman struggle to hold him up