Seiuchin (セイウチン), known in the English dub version as Wally Tusket, is a fictional character from the anime and manga series Ultimate Muscle (Kinnikuman: Nisei). He is a supporting character and a close friend of Mantaro Kinniku, enough that the two consider each other to be brothers. He has a mother and sister also present in the show: Suzie and Dorothy.
A walrus Chojin (seiuchi is Japanese for walrus), Seiuchin is the friendlier and easygoing member of the New Generation. He greatly admires Kinniku Mantaro, and in many ways is a lot like him, the two of them always being hungry and seen eating food all the time (Seiuchin is usually seen carrying around a big fish). He is the Number 2 student of the Hercules Factory First Years and has a lot of heart and spirit, but his kind and gentle personalty wan lead to weaknesses in the ring.  He is originally assigned to defend Hokkaido, an area in Japan best fitted for Seiuchin's environment.
Seiuchin has a mother Suzie and a younger sister named Dorothy who each resemble Seiuchin a lot. His father Robert died in a fishing accident when he and Dorothy were young. Seiuchin's mother taught him how to swim when he was a younger walrus. His family is usually around to support Seiuchin in his matches, and Seiuchin cares deeply for them.
In the final story arc, Seiuchin has grown sick of Mantaro's numerous thoughtless remarks about him and leaves the Justice Chojin side to form the Hell Expansions with Neptuneman. Neptuneman awakens Seiuchin's ferocious animal instinct, transforming him into a blood thirsty beast. Ever since, Seiuchin has appeared as an enemy of Mantaro and the others.
In the Japanese version, Seiuchin refers to himself in the first person as Ora (オラ) and refers to Mantaro as Aniki (アニキ), a term of respect for someone considered a brother. He refers to his mother as Oga (おがぁ) and father as Odo (おどぉ).
The Graduation Ceremony is Seiuchin's first appearance, and he appears to be a lot more serious and menacing.
During Mantaro's match against Tel-Tel Boy, Seiuchin leaves his post to come to Tokyo where he can help Mantaro out, after hearing that Gazelle was easily beaten.  During the match, he is seen sitting with Terry the Kid, Gazelleman, and The Adams, each wearing Mantaro's lame t-shirts. While the other second generations choose to take off the t-shirts, Seiuchin wears his just to be nice.  During the match Wally and the others comment about Mantaro and Tel-Tel Boy. When the others are doubting Mantaro, Seiuchin stands up for him and says that he believes Mantaro can win. Mantaro finally gets with it and unleashes his Kajiba no Kuso Djikara.
After Tel-Tel Boys's defeat, the next dMP member, MAXman, steps up to take on Mantaro. Mantaro is too tired and weak to fight, and Kevin Mask gives him an hour or rest. Kevin and MAXman get into an argument, and MAX pushes Kevin aside. Seiuchin, being the friendly chojin that he is, helps Kevin Mask stand up, only to be shoved away.  MAX, being impatient, decides to take on another Justice Chojin while Mantaro recovers. With Gazelleman already been defeated, the second member of the team is called forth, which turns out to be Seiuchin, who apparently had no idea and is busy eating.  The Kid and The Adams are both surprised and wonder how Seiuchin is second, and it is explained that Seiuchin's scores in Martial Arts and Martial Arts theory were near the top. Seiuchin may have a 'friendly giant' image, but in the ring he is a fearsome beast.
Seiuchin does not want to fight because he is eating, but Seiuchin gets into the ring due to a poke in the butt by Mantaro, which causes Seiuchin to leap into the air and land on the ring.  Seiuchin begins to pound on MAXman, having the upper-hand. Seiuchin sends a ton of brutal moves on MAXman, and is surprising everyone with how well he can do techniques and how easily he breaks out of MAXman's holds, and is about to finish him off with a kick, just as MAXman asks to catch his breath. Being the nice guy that he is, Seiuchin lets MAXman take a breather, but fails to realise that this was a trick. MAXman viciously strikes back at Seiuchin, leaving Seiuchin powerless to fight back. During the match, Seiuchin notices that Mantaro was not really weak and tired, because he is busy eating all the food.  MAXman morphs into a shoe, and slams Seiuchin face first into the ground with a nasty suplex. Seiuchin manages to recover, and asks MAX if that was his best shot. MAXman finishes Seiuchin in shoe form by slamming the walrus into the canvas, calling the move the Big Boot Impact, the shoe's tip slamming through Seiuchin's midsection. Seiuchin's blood splatters onto Meat, Kid, Gazelle, and Adams. Seiuchin is defeated and put on the stretcher. 
Before he is carried out of the arena, he asks Mantaro if he saw the last move, and explained that he was already defeated after the suplex, but took the last beating so Mantaro can observe MAXman's movements and hopefully defeat him in his next match. As he is being carried off by the paramedics, his bandanna falls off, which Mantaro wears on his forehead to remind him of Seiuchin's loss. During Mantaro's fight against MAXman, Wally is at the Superman KO Hospital watching the match on television. After watching Mantaro defeat MAXMan, Wally cries in joy and is thankful. 
After the Second Generation team (The Muscle League) is mentioned to be lazy champions who spend more time having fun than training, Harabote Muscle sends in the Hercules Factory's second semester graduates, known as the Generation Ex, to replace the Muscle League. 
In the first round, Seiuchin is set to battle Clioneman.  The match is located on a stone foot of Achilles' Heel in the middle of the river, happening the same time as Gazelleman's match against Jade, which is located in Yokohama International Stadium.  Seiuchin at first has the upper-hand against Clioneman in a test of strength, but as it came to skill, Clioneman had Seiuchin beat with moves and speed. Seiuchin eventually begins to pound on Clioneman and get him into holds, but Clioneman's body is able to slip out. Clioneman morphs his arms into blades and ice shields, slashing and blocking Seiuchin, but Seiuchin wouldn't give up.  Seiuchin eventually gets knocked into the ground, and becomes absorbed into Clioneman's watery body. 
Seiuchin finds himself unable to escape no matter how many punches he throws, but with the help from his mother and sister, who are watching the match, Seiuchin manages to break free after a fish is thrown at Clioneman.  Seiuchin uses the fish to power up, and gives Clioneman a pile driver. But even after all that, Clioneman still manages the upper-hand, by morphing into a magnifying glass and sending fire bolts at Seiuchin.  Even with the encouragement of his family, friends, and many fans whom Seiuchin has helped out with around the city, Clioneman defeats Seiuchin by causing him to black out from the water.  Even though Seiuchin is defeated, Clioneman uses his XYZ Crash on him, and Seiuchin is impaled by the sharp ribs in Clioneman's body. 
Seiuchin's appearance in this arc takes place during Mantaro's fight against Fork the Giant. His part - as the protector of Hokkaido - is to bring Fork the Giant to the wrestling ring, by pulling him forcefully with chains, but he is later attacked by Fork the Giant with his Pinned Insect attack.  He is then held hostage, with Fork the Giant threatening to take his life should Mantaro not show up for the match.  Mantaro rescues Seiuchin in time, and gets Seiuchin medical attention. 
Seiuchin is celebrating on Earth with his teammates, when they learn about the retirement of Harabote Muscle, and at this point a new Chojin Olympics is announced by Ikemen Muscle.  Seiuchin, along with the others, depart to their homelands, and Seiuchin returns to Ireland, to prepare and enter the preliminaries. On the TV Seiuchin is seen defeating Sharkman, and becomes the champion of Ireland.  During the next preliminary round of the Chojin Olympics, Seiuchin and the others compete against other Chojin in a "Rock Paper Scissors" match. Seiuchin defeats his opponent and advances to the next round.  Though his opponent's name isn't mentioned, and is only shown for a second, he appears to be a chojin in a pig costume. 
Seiuchin and the gang later helps Jade train for the Chojin Olympics. Seiuchin spars with Jade, Jade is taunting Seiuchin, saying that all his blubber slows him down, Seiuchin responds and charges Jade, who puts him in a headlock and slams his head down onto the canvas. Seiuchin presses off, sending Jade flying to the other side of the ring. Jade then charges at Seiuchin, only to get their spar interrupted by Kevin Mask.
After the Kevin Mask vs. Ilioukhine match, Meat is badly injured while rescuing Ilioukhine from Kevin's wrath, leaving Mantaro without a trainer. Seiuchin and Kid are the candidates who could fill in, but according to the rules, as Japanese Representative, Mantaro must have a Japanese Second.
After Mantaro's loss to Kevin Mask, Seiuchin, Kid, Gazelleman, and Check Mate try to cheer him up. He later sits at ringside for Hanzou's fight with Gepparland and joins forces with Kid and Gazelleman to help Mantaro train for his match against Ashuraman.
Seiuchin is one of the Time Warp 8 and travels back in time to the days of the Legends (right after the
Dream Chojin Tag Arc conclusion) in order to save Robin Mask from being killed and, by extension, Kevin Mask from being erased from time. However, his duties end up being limited to laundry duty. When the Tag Tournament is announced and everyone is pairing up, Check Mate offers to team up with him, but he turns him down. Neptuneman then appears, having stowed away on the time ship, and chooses Seiuchin. He claims his reason for this is that he wishes to bring out the untapped cold-hearted, beastly power of Seiuchin. When Mantaro complains about Neptuneman picking a Bumbling Chojin like Seiuchin over himself, Seiuchin throws his apron away and tells Mantaro Sayonara, referring to him by name instead of Aniki, leaving Mantaro utterly speechless. Seiuchin goes after Neptuneman and the Hell Expansions (ヘル・イクスパンションズ) are formed.
In a cave, Seiuchin is chained up and hung from the roof as several bats gnaw away at him. Neptuneman then taunts him with the story of The Walrus and the Carpenter. Hearing of the brutal nature of the walrus, Seiuchin is transformed into a feral beast and breaks the chains. He then grabs and devours each bat. Check Mate arrives and tries to reclaim Seiuchin, but he is overpowered and defeated with a Cross Bomber so powerful, the skin on his face is knocked off. Before the tournament, Neptuneman begins feeding himself and Seiuchin special crystals that fuel their new finishing move, the Optical Fibre Cross Bomber.
When they arrive at the Tournament, Seiuchin is carrying a casket. He drops it when he grabs and devours a bird, and out of the casket comes a faceless Check Mate. During the preliminary Battle Royal, they face off mainly against the Muscle Brothers Nouveau (Mantaro and newcomer Chaos Avenir). They almost hit Mantaro with their Optical Fibre Cross Bomber, but Ilioukhine and Barrierfreeman save him and become victims in his place, the skin of their faces knocked off. Seiuchin then attempts to eat Barrierfreeman's face, but is restrained by Neptuneman who wants to add the face to his collection.Seiuchin and Neptuneman first faced the Super Trinites (Jade and Scarface). Jade had trouble fighting without remembering the old Seiuchin, leaving himself wide open for attacks at times. After Jade tagged in, Seiuchin and Neptuneman received a brutal beat-down from Scarface. Seiuchin, however, soon regained the advantage and even breaks free of the Ultimate Scar Buster, biting Scar's neck upon impact with the canvas. Jade then attacked Seiuchin and Neptuneman with his new technique, Brocken's Repatriation. Seiuchin and Neptuneman then prepared to hit an exhausted Jade with the Optical Fibre Cross Bomber, but Scarface shoved Jade out of the way and became the victim instead, losing his face. Soon after, Jade is blinded by the Mask the End and has his neck broken by the Optical Fibre Cross Bomber, resulting in a victory for the Hell Expansions.
The Hell Expansions are set to face the Hell's Bears next. During the fight, he fought against Warsman's partner Michael, who is later revealed to be Mammothman in disguise. During the fight, Seiuchin finally got back to his senses; but unfortunately, when he does, Neptuneman betrays him, as does Mammothman to Warsman, and both knock Seiuchin's face off with an Optical Fibre Cross Bomber.
Story: Anime Changes
Wally makes his first appearance while training with a bunch of other second generation chojins, introducing himself to Mantaro and saying that he is honoured to meet the son of Suguru Muscle Suguru Kinniku. He also mentions that he likes fish. Throughout this arc he is seen going through strict training lessons with the other chojins, and speaking out comments during certain scenes. There is a part where he and Mantaro lazily decide to sit out of training and eat fish, just as both of them are thrown into a frying pan, both of them humorously screaming from the heat. Wally graduates from the Hercules Factory, though his fight with one of the Legends is never shown.
During the Graduation ceremony, Wally is awarded Best use of Weight, and is counted as #2 in the Hercules Factory, just second to Gazelleman. He is then assigned to defend Hokkaido, a snowy area of Japan, which is perfect for his environment.
In the anime, Seiuchin returns during the battle against Sunshine's Nightmares, spending most of the time witnessing the matches, and does not really have much of an importance except for being able to support Terry and Mantaro. He is counted as number 7 in a wrestling popularity contest though.
In the anime, Seiuchin is defeated when Clioneman uses his XYZ Crash on him, which damages his body. Seiuchin is seen again during Mantaro's semi-final match against Clioneman, laying in the hospital and unable to do much. Near the end of Mantaro's match, Seiuchin, Gazelle, and Kid show up, each of them still wrapped in bandages, and begin cheering Mantaro on to defeat Clioneman. During Jade's match against Scarface, Seiuchin is seen sitting with his fellow Muscle League buddies, and is completely recovered.
On the night before the Finals, Seiuchin and the others encounter Scarface out on the street. Gazelle and Seiuchin are the first to attack, but get easily beaten, and end up in the hospital again. Seiuchin spends the rest of this arc in the hospital watching Mantaro's match against Scarface.
The preliminaries are a game of Beach Flags, using three chojin at a time, and the goal is to save a falling damsel. Seiuchin is one of the first to go. In the anime, his opponents are Ilioukhine (Comrade Turbinski) and Power Command Joe (in the original manga, Seiuchin's spot is filled by Mad Penguin). As the race begins, Seiuchin and Power Command Joe are running side-by-side, until the cyborg attacks Seiuchin, knocking him backwards. Seiuchin manages to get up and continue running, but ends up eliminated after Ilioukhine finishes the race.
This is an anime-only filler arc, which breaks the Chojin Olympics in two halves.
After the Chojin preliminaries were done with, a team of evil Chojin known as the Poison Six Pack kidnap Rinko, Tamaki, and Keiko. Seiuchin and the other Justice Chojin go to rescue them. Seiuchin witnesses Terry the Kid and Jade defeat the first two foes in a tag battle. The second tag-team match is being held over a lake, which is where Gazelle and Seiuchin battle against Puri-Puri Man and El Kaerun.
Seiuchin spends the first part of the fight watching Gazelleman fight Puri-Puri Man, and encourages his partner not to listen to butt-head's insults. After some harsh beatings on Gazelle, Seiuchin tags in and battles El Kaerun with brute strength. Like Gazelle, Seiuchin is taunted about the fact that he is never winning many battles, and being called a loser. He is later on knocked down into the green ooze that they battle above, struggling to stay up. With the encouragement from his mother, who tells him to remember his swimming lessons, Seiuchin manages to get out of and help Gazelle. Seiuchin's mother and sister later on get knocked into the green ooze (caused by El Kaerun), and Seiuchin leaves his faith in Gazelle to keep the French Connection busy (Check Mate fills in for Seiuchin).
After Seiuchin heroically saves his family, he returns to the fight and saves Gazelle from being attacked from behind by El Kaerun. He and Gazelle beat up their foes, proving that they aren't jokes, and unleashing their special techniques. Seiuchin uses his Sky High Driver on El Kaerun, smashing him into the ring and defeating him. Seiuchin gets teary eyed over Gazelle's first official win. Keiko is rescued, with Seiuchin being the one to catch her. During Mantaro's match against Baron Maximillian (the final fight for this arc), Seiuchin and the others shout out their support for Mantaro, and they all help out in saving Mantaro and Rinko from falling. At the end, he and the others are getting hyped up about Mantaro and Rinko, who are supposedly about to kiss.
- Megaton Dropkick (メガトン・ドロップキック)
- Dublin Whirlwind (Salmon Splash)
- Ice Rock Driver (アイスロックドライバー)
- Walrus Reverse Fall (海象滝のぼり(セイウチ・リバース・フォール))
- Cyclone Ocean Kick (サイクロン・オーシャンキック)
- Walrus Tooth
- Merciless Hammer (無慈悲の鉄槌, Mujihi no Tettsui)
- Murder Bite (マーダー・バイト)/Murder Tooth
- Needle Fur
- Polar Bear Catch Drop (北極熊捕獲落)
- Seiuchin Lariat (セイウチンラリアット)
- An anime original technique.
- Spiral Torpedo (スパイラルトーピードー)
- An anime original technique.
- Sky High Driver (スカイハイドライバー)
- An anime original technique. Seiuchin turns his opponent upside down and jumps into the air. As he comes down, he slams his opponent face-first into the ground.
- Hercules Factory First Year No. 2 Student
- Ireland Chōjin Youth Grand (U-18) Champion
- 1st Kinnikuman Nisei All Chojin Dai Shingeki Popularity Contest (24th Place)
- Hercules Factory First Year Graduate
- Japan Stationed Chojin - Hokkaidō Region
- Team Aho
- The 8 Time Warp Chojin
- Bumbling Chojin (ヘボ超人, Hebo Chōjin)
- Laundry Chojin (洗濯超人, Sentaku Chōjin)
- Emperor of the North (北の帝王, Kita no Teiō) (as a Perfect Chojin)
- Win/Loss Record (Singles)
- X Maxman (Big Boot Impact)
- X Clioneman (XYZ Crash)
- O Sharkman (STF)
- O Sea Devil (Arm Lock) (96 mins, 43 seconds) 
- O El Kaerun (Sky High Driver) (anime only; tag match with Gazelleman) (Anime movie: Spiral Torpedo; tag match with Gazelleman)
- X Puripuriman (V-Jump)
- O Bath the Shower (Salmon Splash) (V-Jump)
- Win/Loss Record (Tag)
- Hell Expansions (Neptuneman)
- O Check Mate (Cross Bomber)
- Δ Muscle Brothers Nouveau (Kinniku Mantaro and Chaos Avenir) (Interference)
- O Fireball Flying Fogey Squad (Barrierfreeman and Ilioukhine) (Optical Fibre Cross Bomber)
- O Super Trinities (Jade and Scarface) (Optical Fibre Cross Bomber)
- X Hell's Bears
- Win/Loss Record (Other)
- X Ilioukhine and Power Commando Joe (Beach Flags race) (anime only)
- Favourite Food: Raw fish, Ice
- Hobbies: Collecting Mantaro's T-Shirts
- Theme Song: "With All Your Might! Seiuchin" (精一杯!セイウチン, Sei'ippai! Seiuchin) by Takumi Yamazaki
- Age: 14