Hamato Yoshi
Biographical information

Lou Jitsu (former stage name)
Lou Rat-Jitsu
Rat Jitsu (Battle Nexus stage name)


Dad, Daddy, Father, Papa, Pop, Pops (by his sons)
Splints (by April O'Neil)
Snuggle Muffin Beefcake, Huggypoo, Fuzzy Cuddlelupagus (by Big Mama)
The rat (by Baron Draxum)



Weapon(s) of choice

Walking staff
Remote control
Fish and ladders (formerly)


Martial arts movie star (formerly)
Battle Nexus competitor (formerly)
Father/sensei of the Mad Dogs


Raphael (human mutation son)
Leonardo (human mutation son)
Donatello (human mutation son)
Michelangelo (human mutation son)
Piebald (mutation daughter)
S.H.E.L.L.D.O.N. (grandson created by Donatello)
April O'Neil (fellow Hamato Clan)
Hamato Atsuko (mother)
Hamato Sho (maternal grandfather)
Hamato Karai (ancestor through Sho)
Oroku Saki (ancestor through Karai)

Physical description

Human-born mutant rat (currently)


3' 0"


Grey/white (as a mutant)
Black (as a human)

Eye color

Black (as a human)
Yellow sclerae (as a mutant)

Out of universe information
First appearance
Voiced by
Teachers and Students

"I have been living large long enough. I shall no longer deny my destiny! Hot Soup!"
— Hamato Yoshi

Master Splinter, once known as Hamato Yoshi and professionally as Lou Jitsu, is a descendant of the Hamato Clan, a former martial arts movie star, and the biological father and (sometimes) sensei of the Turtles.

Physical Appearance


As a human, Hamato Yoshi was a Japanese man with straight black hair styled in a pompadour, black eyes, tan skin, and a lean figure. His attire usually consisted of outfits resembling wingsuits with a pair of yellow glasses worn over his eyes.


Splinter is a mutant rat with long white hair styled half up into a bun, a white beard, white bushy eyebrows, grey fur, and a short, plump figure. His legs are light pink and from the elbows down, his arms are also light pink (with his hands having five fingers instead of the usual four). He has yellow sclerae, a dark pink nose and tail, black whiskers on his cheeks, and a nick in his right ear. He wears a brown yukata with yellow trim and the Hamato Clan emblem placed on its heart. He also wears a black hair tie.


Splinter, unlike his previous incarnations, is laid-back and lazy. He is absent-minded and sometimes attempts to stir up mischief and trouble with his sons when bored, including stealing the Turtle Tank in "The Fast and the Furriest." Splinter came off as an extremely flawed (albeit loved) father figure; he often treated his sons flippantly and was mentioned to not spend much time in family outings ("Turtle Tots", "Turtle-dega Nights: The Ballad of Rat Man"). However, he is shown to take action when needed, like in episodes such as "Origami Tsunami" and "Mrs. Cuddles." As shown in "The Evil League of Mutants," Splinter deeply cares about his sons and their safety.

How strictly Splinter treats the Turtles can vary. He slowly grew more serious as the first season progressed, especially after learning of the existence of the Shredder. Despite his previous indolence, Splinter became quite serious in training the Turtles to perfect their fighting skills, albeit in unorthodox ways (e.g., Lou Jitsu movies). This apparent contradiction was eventually explained, as in the past he developed a distaste for fighting, refusing to put himself (or his sons) in that position again.


Childhood and Rise to Fame

Hamato Yoshi is a descendant of the Hamato ninja clan who defeated the Shredder 500 years ago and trained themselves to be warriors to fight against the Foot Clan and prevent the Shredder's return. When Yoshi was just a boy, he heard the story of how the Shredder was defeated from his grandfather, Sho, but on that same day, Yoshi's mother, Atsuko, left her father and son so that she can perform her duty as a Hamato, which greatly saddened Yoshi.

For many years afterwards, Yoshi trained under Sho in martial arts so that he may defeat Shredder should he be resurrected, quickly becoming a master of it. However, Yoshi's sadness over his mother leaving him eventually turned to bitterness towards his own clan, leading him to disbelieve the existence of the Shredder. Then one day, as a teenager, Yoshi entered an argument with his grandfather, which led to him deciding to abandon his family duties so that he can pursue his dream of going to Hollywood to become a movie star.

Using the skills he was taught, Yoshi quickly rose to fame and fortune as the action star known as "Lou-Jitsu". Then one day, he was visited by Grandpa Sho, who demanded that Yoshi end his career so that he can come back home to fulfill his true destiny. However, Yoshi sternly refused one more time before closing his trailer's door in his face. Seeing that Yoshi has truly cut ties with his clan, the saddened Sho chose to respect his grandson's wish and left, never to speak to him again. Yoshi watched from the window as his grandfather walked away, slightly remorseful for he treated his former teacher.

Kidnapping and Mutation

When shooting for a film, Yoshi met Big Mama, who drove his trailer, and the two started a romantic relationship. However, Yoshi was unaware that she was a Yōkai, despite some obvious signs. After attempting to propose to her, she forced him into the Battle Nexus , where he triumphed over his opponents. Sometime later, Yoshi had sworn off fighting in the Nexus and tried to resume a more peaceful lifestyle where he wouldn't be so violent towards others.

However, his fame in the Battle Nexus attracted the attention of Baron Draxum, who wished to use his DNA to mutate an army that would serve him. Draxum, with the help of Huginn and Munnin, brought Yoshi to his laboratory to carry out his plan. Once Yoshi realized Draxum was going to use him to mutate the Turtles from their natural state, he objected, but was too late. Draxum put them in capsules of ooze and it was through this process that they were mutated from ordinary reptiles, making Yoshi the biological father of their human genes. Unwilling to watch animals be turned into monsters for Draxum's cause, Yoshi freed himself and Draxum's experiments. In the midst of his escape, he tried freeing the rat from his Battle Nexus cell as well. In turn, it bit him as he was exposed to the ooze, resulting in his mutation. Huginn and Munnin destroyed the laboratory and it went up in flames, leading Draxum to believe that the Turtles had been killed in the fire. Yoshi escaped with the Turtles, however, but he doesn't remember everything from his transformation into his current form.

Splinter remained unaware of his sons' contact with Draxum and the Foot Clan until the events of "Shadow of Evil". Upon discovering evidence of the Foot Clan, he impersonated a teenager and managed to spy upon his enemies, discovering that they were reassembling the Kuroi Yōroi. Realizing that this foreboded the possible return of the Shredder, Splinter pretended to be a member of the Clan in order to take a piece of the armor. This attempt was thwarted by Draxum and, unwittingly, his sons. Upon escaping without the armor piece, Splinter promised to tell his sons "everything" and stated that they were "way behind" on their destiny.


Once human, now a mutated rat, Splinter is an eccentric mentor to his turtle sons, training them in the art of ninjutsu. Well, when he's not watching game shows and Lou Jitsu movie marathons.


As reflected in his status as the most popular martial arts movie star of all time, Splinter is a very skilled fighter, capable of defeating all four of his sons at the same time even when out of shape. He has also shown to be an extremely adept improvisational fighter, using items such as fish and ladders as weapons.



  • Hamato Yoshi's parent(s):
  • Raphael: Apart from Mikey, Raph and Splinter seemed to have the most conversations that showed their bonds of family. In the episode "Mrs. Cuddles", Splinter helped Raph defeat Mrs. Cuddles. After locking her away, Splinter announced they should free his brothers and April, who were all taken captive by Mrs. Cuddles. However, he then says "Eventually", being well aware the situation was their fault due to teasing Raph over his fear of the puppet. In the season 2 finale, Splinter demotes Raph from Mad Dogs leader and gives the position to Leo.
  • Donatello: Splinter has a somewhat difficult relationship with Donnie. He trusts Donnie to take tasks more seriously and Donnie likes getting attention from him.
  • Leonardo: Leo is the one who gets on Splinter's bad side most of the time with his obnoxious antics. But there are times that Splinter is very impressed with his skills. In the last part of the season 2 finale, Splinter promotes Leo to Mad Dogs leader.
  • Michelangelo: Splinter loves his most affectionate son. Mikey helped Splinter improve his relationship with Draxum in "Hidden City's Most Wanted".
  • April O'Neil: As a close friend of the family, April is much like a big sister to the Turtles. But April's relationship with Splinter is not quite like that of Splinter's relationship with his sons; Splinter and April are not responsible for or answerable to one another other in the ways a father or daughter would be. They are nevertheless still close friends, no matter how badly Splinter behaves or how strongly April criticizes him. Splinter isn't hesitant to express his appreciation for April's talents, even as he seldom expresses similar appreciation to his own sons who crave it from him. It was not difficult for Splinter and his sons to regard April as a kind of surrogate family, but later on April would formally be acknowledged by clan matriarch Hamato Karai as truly being a member of the Hamato Clan.
  • Piebald: Piebald was Splinter's beloved pet fish a year prior to the start of the series. After she was mutated, she expressed that saw Splinter as her father. They have since gotten along well, conspiring along with Franken-Foot to play a prank on the Turtles for having originally flushed Piebald down the toilet and lying about it.
  • S.H.E.L.L.D.O.N.: When Donnie first invented S.H.E.L.L.D.O.N., his first tech demonstration was to show how S.H.E.L.L.D.O.N. could make Splinter's life more convenient. S.H.E.L.L.D.O.N. was also made sentient in his own right, and when Draxum had captured the Turtles and held them hostage in "End Game", Splinter recruited S.H.E.L.L.D.O.N. as part of a B-Team (along with April, Bullhop, Franken-Foot, and Todd) to go rescue them. Later, when Donnie upgraded S.H.E.L.L.D.O.N.'s software to version 13 and S.H.E.L.L.D.O.N. started behaving like an obstinate teenager, Donnie would start frequently yelling at S.H.E.L.L.D.O.N. and handing out harsh, arbitrary punishments. Mikey pointed out that the way Donnie was treating S.H.E.L.L.D.O.N. was the same way Splinter treated Donnie, establishing a multi-generational pattern of parental dysfunction. This also acknowledged that S.H.E.L.L.D.O.N. was effectively Splinter's grandson, though the two were never shown interacting much after S.H.E.L.L.D.O.N.'s first appearance. S.H.E.L.L.D.O.N. would later sacrifice his own life trying to save his family from an onslaught by the Shredder during the destruction of their lair.
  • Hamato Sho:
  • Hamato Karai:

Friends and Allies

  • Stanley / Bullhop: For a time, Bullhop lived in the lair with Splinter and the Turtles as they helped Bullhop adjust to his new mutation. Splinter and Bullhop were never shown interacting much, but when Draxum had captured the Turtles and held them hostage in "End Game", Splinter summoned Bullhop's help as part of a B-Team (along with April, Franken-Foot, S.H.E.L.L.D.O.N., and Todd) to go rescue them.
  • Todd Capybara: Splinter once entrusted Todd to teach the Turtles wilderness survival training. And when Draxum had captured the Turtles and held them hostage, Splinter summoned Todd's help as part of a B-Team (along with April, Bullhop, Franken-Foot, and S.H.E.L.L.D.O.N.) to go rescue them. Splinter, like so many others, is fond of Todd's lemonade.
  • Baron Draxum: Splinter and Draxum share a complicated history that goes back to shortly before the Turtles were mutated. Draxum was no fan of Lou Jitsu's movies, but he was nevertheless in awe of his formidable might and fiery will and coveted the human warrior's DNA to create formidable warriors who would be raised to serve Draxum. Draxum helped Lou Jitsu escape Big Mama's servitude in exchange for agreeing to be Draxum's laboratory subject. Their arrangement quickly soured when Lou Jitsu opposed Draxum's plan for the mutant turtles and fled with the Turtles who he would raise as his own sons. It wasn't until Draxum encountered Lou Jitsu again in person that he learnt he had become a mutant rat who called himself "Splinter". It was through Draxum in the same instant that the Turtles discovered for the first time that Splinter had actually been Lou Jitsu all along. Later, Draxum captured the Turtles, holding them hostage and demanding Splinter exchange his last piece of the Kuroi Yōroi for their safe release, which Splinter eventually relented to. Draxum and Splinter met again later, after Draxum had already been betrayed by his Foot Clan partners, his life force drained almost to death by the dark armor, become a wanted fugitive unable to return to the Hidden City, and their son Michelangelo shown Draxum the real love of a son. Mikey had tricked Splinter and the rest of his family into having dinner at Draxum's new apartment, but Draxum and Splinter loathed each other and the other sons didn't think much better of Draxum. Mikey's influence would later be instrumental in Draxum coming to a genuine change of heart by willingly risking his own life to save the lives of strangers; from then on, Draxum's sons started to accept him, and he gradually started loving them as his own sons, but Draxum and Splinter were still openly hostile to each other. Later, during a family tourism trip to the Hidden City (where Draxum wore a cloaking brooch to disguise himself from the authorities), Mikey arranged for Draxum and Splinter to be his only company during their outing, in the hopes that he could inspire them to finally get along, After some initial conniving between the two fathers, Draxum's cover was blown, and all three had to hide from the police in a dumpster; here, Draxum and Splinter were finally forced to face each other and talk, at first as a paint-peeling verbal fight about all the reasons they despised each other. But, almost like a miracle, Splinter realized he would never have had his sons in his life if Draxum had not made it happen, and Draxum recognized that he had wronged Splinter and appreciated that they were both fathers of a son who loved each of them, and this was enough for Draxum and Splinter to at least start trusting one another as the other of two parents of these children they had created together. From then on, for the most part, Draxum and Splinter started treating each other more respectfully, at least in front of their sons, and they would join together to fight in the defense of their sons when they were in danger. Later, after the Shredder had destroyed the lair and taken both Draxum and Splinter prisoner without their sons, at first it seemed that Draxum would again readily betray Splinter for Draxum's own self-interest, but Draxum had only feigned betraying Splinter in an attempt to attack their captors; when Splinter apologized for momentarily doubting Draxum's honor, Draxum replied, "You better be." The two fathers were now truly allies, with or without their sons, and would not turn on each other again.
  • Franken-Foot: When Draxum captured the Turtles and held them hostage, Splinter recruited Franken-Foot as part of a B-Team (along with April, Bullhop, S.H.E.L.L.D.O.N., and Todd) to go rescue them. Franken-Foot also once conspired with Splinter and Piebald to play an elaborate horror prank on the Turtles to punish them for previously flushing Piebald and lying about it.
  • Cassandra Jones / Foot Recruit: This Foot recruit was initially ordered by her Foot Clan superiors to watch more Lou Jitsu movies, at a time when none of them even knew if Lou Jitsu was still around, much less that he was a mutant rat who would become their enemy. On this basis, Casey had already come to hold Splinter in esteem, even when they were on opposing sides. One time, when Casey had briefly taken Splinter prisoner, and she came to realize that her brownie business would not help the Foot Clan in the ways she had hoped, the two ended up bonding, with Splinter cheering Casey up with a pep talk and telling her a story about April and her lifetime of perseverance, though without mentioning April by name. From then on, even as enemies, Splinter and Casey considered each other friends. It was later, when Casey felt split between her loyalty towards the Shredder and her desire not to harm Splinter, that she finally made a choice to turn against the Shredder and protect Splinter; very soon after, Casey helped the rest of the Hamato Clan finally destroy the Shredder. No longer bound to the Shredder or the Foot Clan, Casey was finally not just a friend, but also an ally to Splinter and his family.
  • Mayhem: Splinter and Mayhem have not been shown interacting much, but Mayhem as April's pet is a frequent visitor in the life of Splinter. When Splinter had been injured in a fight with Draxum after the latter had started wearing the fully-assembled Kuroi Yōroi, Mayhem teleported Splinter to safety.
  • Sunita: Splinter and Sunita have not been shown interacting much, but Splinter once entrusted her and April to be the lair's house sitters when he and the Turtles intended to head out for some wilderness survival training.


  • Big Mama: Big Mama was the first Yōkai to become a regular part of Splinter's life, back when he was an actor. Big Mama originally worked (or posed) as the truck driver of Lou Jitsu's filming trailer. Lou Jitsu fell for Big Mama and she loved him back in her own duplicitous way. One day, Lou Jitsu asked Big Mama to marry him, but it was then that she revealed that she had always been a Yōkai and kidnapped him to the Hidden City, an act that severed him from human society and forced him to begin a new life in the Hidden City. Big Mama forced him to fight in her Battle Nexus as her mightiest champion. They consequently broke up and Lou Jitsu gradually became a broken man without passion in his life. This was the condition Baron Draxum found him in when Draxum helped him escape Big Mama's servitude. But even after all of that, Splinter admits in "Many Unhappy Returns" that he still yearns for the person Big Mama had once been to him before his kidnapping. When the Shredder was let loose on the world by Draxum and the Foot, Splinter and Leo approached Big Mama directly at the Grand Nexus Hotel for help in subduing him. Big Mama found Splinter even more attractive as a mutant rat and their mutual chemistry for each other proved undiminished even if they now had little reason to trust one another. To Splinter's horror, Leo struck a bargain with Big Mama that involved his own father fighting once again in the Battle Nexus arena against a particularly deadly set of opponents in exchange for a device in Big Mama's possession which could imprison the Shredder. Big Mama treacherously altered the terms of their agreement at the last second, but Leo had already predicted this and ended up outwitting both Big Mama and his father to execute his cunning plan. The former lovers parted on affectionate, if not entirely happy, terms. Big Mama would later use the enslaved Shredder, disguised and now called "Shadow Fiend," as part of a plot to take over New York City and turn it into the new Battle Nexus, which involved enslaving nearly all the city's inhabitants—Splinter included—inside the Mystic Orb that Draxum had once bartered to her. In the course of events, Draxum managed to free himself, Splinter, April O'Neil and the Foot Recruit from the orb on their own, but they were forced to face Shadow Fiend. The ensuing battle ended up backfiring on Big Mama when the Foot Recruit seized control of the Shredder from her. Before this could happen, Splinter arranged an escape for himself, Draxum and their family, and surprisingly also asked Big Mama to escape with them, as the two still loved each other even after all that had happened and Splinter believed there was some redeemable good in her. Splinter ultimately failed to save Big Mama, and she was helpless to prevent a wrathful Foot Recruit from completely toppling her high-rise hotel in revenge for having enslaved the Shredder; Big Mama's own life was spared so that she would have to live with what she had lost. Later, after the Shredder followed Hamato Karai to the Mad Dogs' lair, destroyed the lair and captured Splinter and Draxum, the Mad Dogs tracked Big Mama one more time to her Yōkai hospital bed and told her what happened to Splinter; while Big Mama now had the more-than-well-earned status of being the Mad Dogs' enemy, her love for Splinter was still believably genuine, and she peacefully gave them the information they needed to locate Splinter and save his life. Whenever Splinter and Big Mama are together, even when they meet as enemies, they are quick to tactile affection and addressing each other with endearing pet names.


  • Rupert Swaggart / Meat Sweats: Splinter encountered Meat Sweats while driving the Turtle Tank around New York in "The Fast and the Furriest". He was bribed with food to enter Meat Sweats' truck where Splinter told him about his concept for a restaurant chain, unaware that Meat Sweats intended to eat him. He fled with Meat Sweats in his truck once the Turtles found him, but was eventually abandoned by Meat Sweats despite his protest. Splinter considers "Rupert" to be a worse name than "Meat Sweats".
  • Mrs. Cuddles: Splinter hates Mrs. Cuddles for terrorizing his family and her show taking over his favored TV schedule. He finds Mrs. Cuddles to be ridiculous and her efforts as a cute puppet to be intimidating endlessly amusing.
  • Huginn & Muninn: Huginn and Muninn brought Lou Jitsu to Draxum's laboratory from the Battle Nexus where he met the Turtles and was mutated.
  • The Shredder: The Hamato Clan was in possession of the Kuroi Yōroi's face plate for generations as a family heirloom, which they had come to use as a tea kettle they named Skully. The reveal of the Shredder being real is what led Splinter to take training the Turtles more seriously.
  • The Foot Clan: The Foot Clan are the sworn enemy of the Hamato Clan. Splinter briefly infiltrated their ranks in "Shadow of Evil" to prevent them from resurrecting the Shredder.
    • Foot Lieutenant: Foot Lieutenant was Splinter's boss when he went undercover as a Foot recruit to obtain a piece of the Kuroi Yōroi.
    • Foot Brute: Foot Brute was Splinter's boss when he went undercover as a Foot recruit to obtain a piece of the Kuroi Yōroi.
  • Kristoff Van Bradford: Splinter describes Kristoff Van Bradford as "an atrocious actor who is dishonorable to his core". Splinter hates him for taking over his Lou Jitsu dojos and for his cheating ways of fighting.



  • This is the fourth version of TMNT to have Hamato Yoshi mutate from a human to a rat, the first version being the 1987 TV series, the second version being the Archie Comics' series loosely based on the 1987 series, and the third version being the 2012 TV series.
  • Splinter is voiced by Eric Bauza, the same actor who voiced Tiger Claw in the 2012 TV series.
  • Throughout most of season 1, it was hinted that Splinter was once Lou Jitsu (and Hamato Yoshi).
    • Throughout Lou Jitsu's appearances until "Shadow of Evil", Eric Bauza has been credited as "Additional Voices" and not as "Lou Jitsu".
    • Like with many celebrities, Splinter keeps copies of most of his merchandise. But the episode "Late Fee" suggests he may not have copies of all his own films, as he had rented one of his films and the episode's plot involved his sons' attempts to return it on time.
  • The name "Lou Jitsu" appears to be a pun of the term jiu jitsu, an outdated romanization of the word jūjutsu (柔術), which is the name of a Japanese martial art. The former variation is still used in derivative arts, such as Brazilian jiu-jitsu.
  • Lou Jitsu's human design slightly resembles American singer Elvis Presley and Chinese actor Jackie Chan.
  • According to an interview, the reason that Splinter seemed out of shape is without immediate the threat of the Shredder, Lou Jitsu's growing disgust for fighting, and (based on Baron Draxum's comments) his fear of treating his sons as weapons, he had no exact reason for training the Turtles. However, after they learn about threats such as Baron Draxum and the fact that the Foot Clan is planning to revive the Shredder, he begins training the Turtles more seriously.
  • According to Leo in "Mystic Mayhem", Splinter always falls asleep after eating milk and cake.
  • Lou Jitsu's eyewear as a human strongly resembles Kamina and Simon's sunglasses from Tengen Toppa Gurren Lagann.
  • While in Big Mama's Battle Nexus, Lou Jitsu briefly had a pet rat. This was a reference to previous incarnations of Hamato Yoshi having a pet rat that would later become Splinter.
  • Splinter is the one of only two main characters in "Tales of the Hidden City" who does not get arrested, the other being Mikey.
  • Out of the four Turtles, Splinter refers to Donnie and Leo by their mask color the most.
  • Lou Jitsu's difficulty coming up with good names for the Turtles as shown in a flashback ("Goyles, Goyles, Goyles") might be this continuity's explanation of why they wear different colored masks as opposed to the all red of the Hamato Clan.
  • The running gag of him being unable to tell his sons apart (which is sometimes implied to be intentional teasing) is ironic given each Turtle is a different species in this continuity.
  • Splinter is knowledgeable about sewing. This is shown in "Insane in the Mama Train" when he made each of his sons Hamato Clan jumpsuits.
  • It was revealed in April 2021 from Rise of the TMNT writer Ron Corcillo in a tweet that the explanation behind the difference in Lou Jitsu's natural voice versus his voice in film is the presence of English dubbing over the films from his Japanese era of work such as Teriyaki Shakedown. However, this difference turns into code-switching when Lou Jitsu is seen on a film set in a flashback and can be heard speaking with an Americanized accent.
    • Code-switching (colloquially) is the act of marginalized communities, notably BIPOC, performing the mainstream culture in order to prevent ostracization and violence from others.
    • Even currently, Splinter sometimes changes his voice to an Americanized accent (though not as strongly as in his films) when playing his recurring character, average teenager Randall, as part of his "being perceived as average" gimmick.
    • These moments allude that Lou Jitsu's image could only be ethnic to a certain extent to be palatable for an American audience as determined by his talent manager, thus encouraging him to speak without his Japanese accent and use a stage name.