Augustus Amherst, also known as Renoir, is the 16-year-old deuteragonist of Mutant Ninja Turtles Gaiden along with his new ninja master Raphael Hamato. He is the nucleus of the story's cast of younger characters.
As important as the human boy Augustus Amherst is to the backstory, he is never physically shown, except in Chapter 1: Enter the Renoir when the turtle Renoir is found sitting in a pile of Augustus' blood and severed limbs.
Renoir himself looks like other mutant turtles, with his skin being a unique shade of light green. He is approximately the same size the four Hamato brothers were when they were teenagers, though the brothers have since reached adult size and are very noticeably taller and larger than he is. Renoir wears standard ninja turtle accessories—belt, knee pads, elbow pads and wristbands—which used to belong to Raphael who has long since outgrown them. Renoir's most distinct identifying feature is his dark yellow bandana, whose relatively stiff cloth sticks outward behind his head instead of hanging limp like the bandanas of the brothers do.
In many ways, Augustus was like ordinary human teenagers—he loved his human family, he had good friends from school, he didn't always do well on his schoolwork, he would sometimes talk back to his elders, and he had a powerful teenage libido and attraction to girls. This later trait is greatly amplified as both a personality quirk and a running gag, as he stashes dirty magazines, obsesses over women's undergarments, peeps at girls in private situations, and takes any opportunity to look up skirts or touch lady parts. But he was always still chivalrous and genuinely cared about his female friends, and was particularly close to his sweetheart Davianna Wallace. Augustus is also prone to sudden loud gushes of emotion, such as joy or sorrow.
As a mutant turtle thrust into the exclusive secret world of the Hamato and Jones families and no longer able to live a public life, Renoir has had to improvise to many new and serious situations, and does not always do this gracefully. But he tries to make the best of bad situations, and proves capable of great courage even when he's scared out of his mind. He also deeply craves a return to something resembling a normal life like he had as a human, with family, friends and the things in life he truly loved.
Renoir is not a typical mutant turtle, being unique from the other mutant turtles in that until recently he lived the life of a human boy, Augustus Amherst. But his real nature—and how a human came a mutant turtle—have still not been concretely explained.
In Chapter 18: A Little Deeper in Donatello's World, on the day of Hamato Splinter's death, a younger Maxwell Amherst heard shouting voices from the sewers. It was actually Raphael Hamato, who was screaming "And it's all my damn fault!" Raphael was heavily bleeding onto the concrete at the time from all the wounds he had sustained from the cursed Tōtsuka Sword. Later, when no one was around, Maxwell retrieved a sample of Raphael's mutagenic blood and ran a series of secret scientific experiments, first injecting the blood into a red-eared slider, wondering if it would affect the lab turtle's offspring. In a series of only vaguely-explained events, the baby Augustus Amherst fell into an air duct of the home of Maxwell and his wife Clara. The police were able to find and recover their son, but they also found the discarded remains of many dead baby turtles, along with a red-eared slider whose stomach had burst open. This created a public scandal, and Maxwell was fired from his research job.
In Chapter 1: Enter the Renoir, in a mysterious event on the roof of a Brooklyn Private School, the 16-year-old human boy Augustus Amherst apparently dies, and his friends Shadow Jones and Davianna Wallace discover a blood-soaked mutant turtle sitting in a pile of Augustus' blood and mutilated body parts. Shadow subdues the turtle, which is then taken into police custody. Raphael and Donatello Hamato break the turtle out of police custody and take him to Raph's lair where he intends to train the new mutant in ninjutsu as Splinter had once trained Raph and his brothers. But the young turtle has the authentic memories and personality of Augustus himself, insisting he's the same person. Raph does not believe him, instead assuming the young turtle feels remorse for killing and eating Augustus and is merely pretending to be him. Raph believes it's important not to let him assume that identity, so he gives him a new name—Renoir, after the 19th century French artist Pierre-Auguste Renoir.
In Chapter 2: Reminiscence - Living Memories Beyond Death's Illusions, Raphael takes Renoir to his own funeral to give him closure on the human boy's death, and they confirm that the coffin contains Augustus' mutilated remains. But they are encountered by Shadow, Raph's brother Michelangelo and Augustus' little sister Carole. Renoir reunites with Carole while Shadow and Mikey are alarmed at Renoir's presence and appalled at Raph for bringing him to the funeral. But Renoir is finally able to speak alone with Shadow and demonstrate his unique knowledge and quirky personality to convince her he is really Augustus.
In Chapter 3: Broken Brotherhood - Burden from "Back Then", Renoir hasn't eaten since Raph took him in, so Raph sends Renoir to visit Shadow to be fed. At the Jones Apartment, Renoir is finally formally introduced to Shadow's Uncle Mikey, who tells Renoir about the Hamato family's history and current situation, and how Renoir is now in an ideal situation to help Raph with his problems. When Raphael arrives to collect Renoir, the young mutant witnesses his new master have a drunken emotional meltdown, and witnesses for the first time just how broken and vulnerable Raph really is.
In Chapter 4: Watch Out! Business with the Purple Dragons!, Renoir and Raph are still at the Jones Apartment where Raph is resting off a nasty hangover. After Raph leaves alone, the apartment receives a frantic call from Shadow reporting that Davianna has been kidnapped by the Purple Dragons. When Shadow begs Mikey to help her rescue Davianna, Renoir witnesses another Hamato brother have a breakdown as the now pacifistic Mikey freezes up and refuses to help Shadow rescue Davianna. Shadow angrily denounces Uncle Mikey as a coward, and Renoir leaves to join Shadow as Mikey dejectedly sulks to the floor.
In Chapter 5: Raph Strikes - How to End a Conflict and Start a New One, Renoir and Shadow catch up with Davianna, who is already in the process of being saved from the Purple Dragons by Raphael, who has arrived on his own. Renoir becomes hopeful as Shadow tells Davianna that Augustus is still alive as a mutant turtle, but his hopes are dashed when Davianna immediately assumes that turtle is Raphael. But when Raph starts playing along and pretends to be Augustus out of a misguided attempt to shelter the mourning Davianna's fragile state of mind and to blackmail Renoir into not deserting him, the already antagonistic relationship between master and pupil becomes a rift of outright enmity as Raph has effectively destroyed Renoir's chances of reuniting with his sweetheart.
In Chapter 6: The Actor Who Has Never Performed Before, Renoir watches the television news with alarm as it reports that a mutant matching Donatello's description seized Renoir's sister Carole and wielded her as a human shield against police officers. But Carole turns up safe, telling the reporters that the turtle who grabbed her was a hero who saved her from harm.
In Chapter 7: The Untimely Clash - Raphael vs. Michelangelo, Renoir witnesses Master Raphael having another meltdown, this time barging into Mikey's bedroom and physically assaulting him.
In Chapter 8: The Cowards, as Raph is savagely beating Mikey within an inch of his life and Shadow frantically asks Renoir to help her stop the violence, Renoir freezes up and will not help. The young turtle is still struggling with his identity crisis as Augustus, but is also fed up with being repeatedly dragged into the Hamato brothers' family drama when he cares so little about them to begin with. Shadow finally violently improvises, managing to bring Raph out his rage without Renoir's help.
In Chapter 9: Deeper in the Abyss, now that Master Raphael has been pacified and rage has turned to guilt, Renoir seizes the opportunity to tell Raph off, attempting to cut ties with him forever. But after the dejected Raph leaves alone, Renoir and Shadow begin a shrill argument over Renoir's actions pushing Raph into deeper despair, creating a rift in their friendship. Uncle Mikey firmly instructs Renoir to return to Raph and be there for him in his time of need. Forbidden from staying in the apartment, Renoir first visits Donatello, who is eager to invite the scientifically-fascinating young mutant to live with him. Renoir tells Donatello what had just happened, and the older turtle explains to Renoir the nature of his brother Raph's "rage fits," and how Raph will become violent to himself if there is no one else around. Renoir immediately returns to Raph's lair, finding his master heavily liquored and having cut open all his own old scars. Raph laments hurting the people he loves—Renoir included—and begs his student to kill him. But Renoir instead feels inspired to symbolically cut himself a few times, in an attempt to distress Raph and show him the real effects his self-destructive actions have on the people around him. Renoir still despises Raph, but now conscientiously feels responsible for Raph's well-being, and promises to remain with his master permanently.
In Chapter 10: Rational Voice? Enter Casey and April!!!, Casey Jones and April O'Neil finally return from their second honeymoon, and are surprised to learn that their daughter's friend Augustus has returned as a turtle. To Raph's continued skeptical dismay, the couple are quick to accept Renoir as Augustus, but caution the young turtle that his own family the Amhersts are not likely to do the same even if presented with hard proof. April invites Renoir to attend their upcoming Hamato-Jones family Christmas party, presenting him a chance to make up with his friend Shadow in the wake of their nasty argument.
In Chapter 11: A Prelude to..., Renoir begins what will prove to be a very long and eventful Christmas holiday. Master Raphael takes Renoir to visit his sister Carole, who has been hospitalized for toxic gas inhalation after her incident with Donatello. But there they meet Shadow and Davianna, who are also visiting with Carole. Raph immediately recognizes that Carole's contradictory acknowledgment of Renoir as Augustus will break his own cover with Davianna, and he immediately leaves with Davianna. But Shadow and Renoir's visit with Carole sours as the two teenagers resume the argument they had started earlier. Raph soon returns with Davianna, who has figured out on her own that Raph is not really Augustus, and runs out upset at both Raph and Shadow for lying to her. Raph tells Renoir that he finally believes the young turtle is really Augustus, and that he unsuccessfully tried to tell Davianna. Renoir runs off after her, only to witness Shadow and Davianna being kidnapped together by the New York City Foot Clan renegade Eikichi Gotoh.
In Chapter 12: ...The Crimson Christmas, Renoir is finally making use of his recently learnt roof-hopping skills as he pursues the car whose occupants kidnapped Shadow and Davianna. A NYC Foot Ninja leaps out of the car and discovers Renoir following them. The Ninja attacks Renoir and gruesomely rips out the turtle's left eye before knocking him down into an alley. Desperate to save his friends but writhing in extreme pain, Renoir stops to beg for help from random pedestrians, who only fear or mock him as a mutant turtle. Renoir writhes even more at ordinary people's rejection of him, and he gives up on this futile effort and returns to the rooftops, continuing his pursuit of the car. The car stops at a derelict industrial port where they brutally beat the tied-up Shadow and toss her into the freezing water, leaving her to drown, but Renoir swims down and saves Shadow. Both teenagers are severely injured, but Renoir starts carrying the hypothermic Shadow home to her apartment.
In Chapter 13: Back into the Shadows, Renoir and Shadow crash the Hamato-Jones Christmas party by arriving with severe injuries and a warning that both Michelangelo and Davianna are in extreme danger. Quickly realizing that Mikey had already left through his own bedroom window, the family discuss a plan of rescue. Master Raphael has finally come to love Renoir and doesn't want him facing any more danger, but reluctantly commands Renoir to join them after Donatello coldly points out that Renoir is their only lead to finding Mikey and Davianna's location. But first, Raph gives Renoir a Christmas gift—a pair of tonfas that will become his primary weapons. As Raph and Donnie leave to collect their weapons and Raph's motorcycle, Casey and Renoir go in Casey's Hummer so Renoir can guide Casey from memory.
In Chapter 14: Dogfight!! Up Close and Personal with Remnants of the Foot Clan!, Casey and Renoir arrive at the scene, but discover that Davianna has managed to free herself and is being chased down by an assassin. Casey crashes his Hummer into the Ninja to incapacitate him. Casey then leaves to help Mikey, telling Renoir to protect Davianna. Renoir is alarmed when Davianna complicates their situation by calling 911 on her new cell phone, with Renoir pointing out that the police tend to shoot at mutants on sight without asking questions. But the situation is immediately even more complicated when the NYC Foot Ninja gets up, still alive, and continues trying to kill both Davianna and Renoir. In a moment of desperate cooperation, Davianna helps Renoir kill the Ninja. Davianna becomes upset that she killed another human being, but Renoir gathers his courage and assures her that they did the right thing in defending themselves from a motivated killer. Renoir warns Casey and the Hamato brothers that someone called 911 and the police are coming, but does not tell them it was Davianna who made the call.
In Chapter 15: And So the Pages Turn..., Casey and Renoir have accompanied Davianna to the vicinity of her home. Standing on a nearby rooftop, they observe the police outside her house and Casey realizes it was Davianna who called 911 on them. Unable to go home just yet, Renoir asks Casey to give him a moment alone with Davianna. As Renoir reminisces about their childhood together with Shadow and friends, Davianna finally realizes that Renoir is the real Augustus. As Renoir's eye socket bandage peels off to reveal his severed eye having fully grown back, he realizes that it is only Davianna's opinion about his identity that he cares about. But Davianna counsels him that only he can decide his identity, and they agree to retire the name "Augustus" and call him only "Renoir" from then on. Davianna leaves Renoir with her cherished magatama pendant, and Renoir finally breaks down and sobs.
In Chapter 16: The Leader, Renoir has returned to the Christmas party. He has no speaking lines, but he is shown enjoying friendship with Master Raphael for the first time.
In Chapter 17: Between Cops and Ninjas, Leonardo Hamato's abrupt return home has immediately driven his brother Donatello into a psychological meltdown, and he is desperate to flee—but also to finally collect biological samples from Renoir, who is currently in Shadow's room. Donnie barges in and demands Renoir come home with him, first offering to bribe Renoir with promises of a friendly voice, unexpired food, internet pornography and even access to women's panties, but this only deeply unnerves the frightened young turtle. Donnie grabs Renoir and swears to bring him home dead or alive, but Raph is alarmed to hear this and stops him, finally forcing Donnie to leave empty-handed. April soon returns from the hospital with Shadow, who finally has a chance to sit down with Renoir so they can reconcile their friendship. The remaining turtles are all finally forced to leave when Raph's cigarette sets off the smoke detector which summons the fire department. But as they gather ready to leave, Renoir and Leonardo see each other for the first time, both realizing they are complete strangers.
In Chapter 18: A Little Deeper in Donatello's World, Renoir and the three Hamato brothers are heading to Raph's lair to start a new life together. Renoir guides Michelangelo to a manhole for his first visit in years, but the two take an opportunity become acquainted—again, since the events of this night have resulted in the resurrection of Mikey's long-abandoned ninja identity and funloving personality, making him a completely different person from Shadow's calm and serious uncle he had first met. Mikey counsels Renoir on the importance of smiling, and how this positive reinforcement makes hard times seem less hard. Renoir then heads off on his own to visit his sister Carole, but is stopped on a rooftop by Nobody demanding to see Leonardo. At first Nobody confuses Renoir for one of the four Hamato brothers and Renoir confuses Nobody for a (NYC) Foot Ninja, which both deny. When it becomes clear that Renoir is actually the "feral mutant" who "killed" Augustus Amherst, Nobody tries to arrest Renoir for the crime, but Renoir emphatically announces that he is Augustus Amherst and can prove it. Nobody monitors Renoir as he crawls into Carole's bedroom window for a little Christmas visit. But their father, Maxwell Amherst, discovers and attacks Renoir. But Renoir quickly unnerves Maxwell by declaring knowledge of family secrets only Augustus would know. Renoir has just provided the very proof Casey warned him his parents would likely reject.
In Chapter 19: Fragments of Truth Inside His Mind, Renoir claims a legal document from one of Augustus' secret stashes, intending to prove his identity to Nobody who is still waiting outside. Renoir's personal knowledge, uncannily matching personality and his genuine concern for Carole, are all deeply stunning and unsettling to Maxwell. Unbeknownst to Renoir, Maxwell recalls secrets of his own—he once gathered a sample of Raphael Hamato's blood and conducted experiments on laboratory turtles, and finally realizes that a mysterious incident involving Augustus as a baby may be related to the discovery of this mutant turtle who is so much like his own human son. Maxwell and Renoir discuss Carole's asthma, which she developed after inhaling toxic gas during her incident with Donatello. Carole still regards him as a hero who saved her life, but Renoir has become deeply suspicious of Donatello, whom he warns may not actually be a good person. Renoir returns to Nobody with the document, only to discover that Nobody didn't actually care about proof—he wanted to catch Renoir in the act of killing and devouring his own sister—but since this didn't happen, he declares Renoir "clean" and reiterates his demand to meet with Leonardo. But Renoir is furious that Nobody gambled Carole's life and refuses to help him.
In Chapter 20: Adjusting to the Present, Leo and Mikey move into the lair Raph already shares with Renoir, and Leo and Renoir formally introduce each other. Leo also has questions and comments about Raph's role as Renoir's master.
In Chapter 22: The Witch-Hunt of a Bloodline, Renoir slips out of the lair at night to chat with Davianna over Shell Cell, having his first opportunity since becoming a turtle to casually reconnect with her as a friend. Leo has also snuck out secretly to meet up with Karai, but discovers Renoir talking in the sewer tunnel, coming just in time to hear Renoir confide to Davianna how uncomfortable Leonardo makes him. Unable to get past Renoir undetected, Leo stops to talk with Renoir for a bit, and notices the magatama pendant Davianna gave him. When Leo realizes that the pendant was given to Renoir by a Japanese girl, Leo is suspicious and asks to see the girl's photographs, but Renoir assumes he is asking for naughty pictures of an underage teenage girl and refuses. Leo believes Renoir won't follow him, but he is mistaken, and Renoir shows up in the middle of Leo's meeting with Karai, Sadao and Nobody in a most inopportune moment when Leo's dark side has been unleashed. Alarmed, Renoir assumes Leo is under attack by the (NYC) Foot Clan, accuses Nobody of lying about not being a Foot Ninja, and prepares for battle. Leo uses the distraction to get away even as Renoir is wounded by shuriken. Renoir later catches up with Leo, who informs him that Nobody is the Hamato Clan's ally.
Renoir has the same fundamental abilities of other mutant turtles, with one important exception—his mutant healing ability is twice as powerful as that of the Hamato brothers. In particular, Renoir's left eye was yanked out and amputated on Christmas Eve, but completely regenerated and grew back within hours—something Raphael Hamato's bad left eye hasn't done in 17 years.
Renoir's ninjutsu is very rudimentary, as he has only recently begun training and doesn't have nearly the skill the Hamato brothers did at his age. With Master Raphael's instruction he has become more physically fit and has learnt new skills like traversing building rooftops, though he still has less strength, speed, stamina, stealth and finesse overall than the Hamato brothers. Renoir is also a decent swimmer, which was a skill Augustus Amherst already possessed.
Initially, Augustus Amherst had no fighting skills—his childhood friend Shadow Jones would protect him for bullies, and occasionally beat up Augustus herself. After becoming Raphael Hamato's ninja student, Renoir was initially given no weapons, with his training focusing on fundamental issues of fitness, balance, strength and so forth.
It wasn't until Chapter 13: Back into the Shadows that Master Raphael gave him a pair of tonfas as a Christmas gift. That very Christmas Eve during an attempt to rescue Michelangelo Hamato and Davianna Wallace, Davianna helped Renoir use the tonfas to defeat Davianna Wallace's Assassin who had tried to kill them, making it the first time either of them had ever killed a person. Recognizing that Raphael had given him the tonfas not just to kill but to defend, Renoir carried the tonfas from then on.
Augustus' little sister. The two have a very close and affectionate brother-sister relationship, which continues even after he becomes a turtle. They can usually only meet together with Shadow Jones' help, as the Amherst parents usually freak out when encountering mutant turtles.
Augustus' mother. Unlike Maxwell, she does not seem to suspect Augustus' true nature as a mutant turtle, and just sees Renoir as a mutant that killed and ate her son.
Augustus' human father, and the scientist unwittingly responsible for turning his son into a mutant turtle. But until this revelation, Maxwell was hostile to the mutant Renoir, blaming him for killing Augustus. It wasn't until Chapter 18: A Little Deeper in Donatello's World that Maxwell has his first real conversation with his son since his transformation, after which Maxwell is still hostile but now also confused, disturbed and secretly ashamed. Unknown to Renoir, Maxwell was responsible for a series of scientific experiments with Raphael Hamato's mutagenic blood, and the former scientist has only recently finally begun to connect the dots in understanding his son's true nature.
The second other mutant turtle Renoir meets in Chapter 1: Enter the Renoir, Donatello helps his brother Raphael break Renoir out of police custody, and bandages Renoir's injury after the young mutant accidentally injures himself. At first, Renoir considers Donatello the more reasonable turtle, preferring his company over the abusive Master Raphael, and Donnie even offers to let Renoir live at his lab instead of with Raph. But Renoir's early confidence in Donatello steadily withers as the scientist's later actions reveal his true nature. In Chapter 6: The Actor Who Has Never Performed Before, Renoir learns from a news report that a mutant exactly matching Donatello's description has temporarily abducted Renoir's sister Carole Amherst, even going as far to grab her as a human shield. Carole insists Donatello is actually a hero who took a police bullet to save her life, but Renoir still has serious reservations about him. Then, in Chapter 17: Between Cops and Ninjas, when the long lost Hamato brother Leonardo abruptly shows up at the family Christmas party and his presence gives Donatello a panic attack, Donnie desperately tries to achieve something he has actually been trying to do since the day after Renoir appeared—bring him back to the lab and harvest biological samples from him as a lab specimen. Donnie impatiently tracks Renoir down and tries to bribe him with a friendly voice, unexpired food, internet porn and even women's panties, and then finally tries to drag him away, declaring that Renoir is coming with him dead or alive. But this highly suspicious display only seriously agitates Renoir and he refuses, forcing Donnie to abruptly leave empty-handed. After this, Raph stops taking Renoir with him when visiting, though Donnie continually asks about Renoir.
Renoir meets Leonardo for the first time in Chapter 17: Between Cops and Ninjas, when Leo meets his family for the first time since leaving 17 years ago. When Renoir and Leo first see each other, they don't recognize each other. It isn't until Leo starts settling into Raph's lair in Chapter 20: Adjusting to the Present that he and Renoir formally introduce each other. As someone who is leader even over Raphael, one of the first things Leo asks Renoir is to evaluate his master. Leo quickly assumes the role of leading Renoir, Raphael and Michelangelo as a team, sometimes interjecting on how Raph treats his student. While Renoir quickly comes to respect Leo and consider him a kind person, in Chapter 22: The Witch-Hunt of a Bloodline, Renoir confides with Davianna Wallace that something about Leo also makes him uncomfortable.
Renoir first meets Michelangelo in Chapter 2: Reminiscence - Living Memories Beyond Death's Illusions at his own funeral, where Mikey is attending along with his niece and Renoir's good childhood friend Shadow Jones. As it turns out, Mikey is not just Master Raphael's brother, but Shadow's uncle, and has lived at home with her since she was a baby. Renoir and Mikey don't get a chance to become formally acquainted until Chapter 3: Broken Brotherhood - Burden from "Back Then", when Renoir comes to Shadow's apartment looking for food because Raph still hasn't fed him. The calm and serious older turtle tells Renoir more about their family history, even giving him full access to the family photo album. After Shadow falls asleep, Mikey puts her to bed, and sternly admits that he doesn't trust Renoir nor does he believe Renoir is Augustus, but has nevertheless entrusted Renoir with all this family information as someone who is in the right position to actually help Raph deal with his despair in a way Mikey no longer can. Renoir witnesses how caring Mikey is as a family member, but in Chapter 4: Watch Out! Business with the Purple Dragons!, he also observes just how reflexively conflict-avoidant Mikey is. In Chapter 7: The Untimely Clash - Raphael vs. Michelangelo and Chapter 8: The Cowards, Renoir witnesses Master Raphael savagely beat Mikey within an inch of his life, but in Chapter 9: Deeper in the Abyss, Mikey still coerces Renoir into returning to Raph and being there to help him. In Chapter 13: Back into the Shadows, Chapter 14: Dogfight!! Up Close and Personal with Remnants of the Foot Clan! and Chapter 15: And So the Pages Turn..., Renoir participates in an operation to rescue Mikey from Eikichi Gotoh's renegade New York City Foot Clan, though is largely in it to save his school sweetheart Davianna Wallace whom Eikichi has abducted as a hostage. In Chapter 18: A Little Deeper in Donatello's World, as Mikey has made a decision to move in with Raph and Renoir is guiding Mikey to a manhole, Renoir and Mikey have their first real heart-to-heart as friends, where Mikey thanks Renoir for helping Raph and apologizes for putting Renoir in a situation that should have been Mikey's to handle. Mikey teaches Renoir the therapeutic effect of smiling during a difficult situation, helping Renoir feel better about his own problems. From this point onward, both Renoir and Mikey are living together in Raph's lair. Though Raph still occasionally beats on Renoir, Mikey is quick to rush to Renoir's side.
Renoir's new ninja master, and indeed the first face he remembers seeing after his transformation in Chapter 1: Enter the Renoir. Unbeknownst to either of them, Raphael's blood was used by Maxwell Amherst to create Renoir—Raphael and Renoir as turtles may actually be father and son. Renoir's relationship with his master is extremely antagonistic and frequently punctuated with strong physical and verbal abuse. Not surprisingly, early on, Renoir hates and resents Raph and takes advantages of early opportunities to be insubordinate, make him suffer or try to escape from him, and Raph in turn refuses to believe that Renoir could have ever once been a human boy, let alone Augustus Amherst. Their relationship grows even more fraught in Chapter 5: Raph Strikes - How to End a Conflict and Start a New One when Raphael starts impersonating Augustus in Davianna Wallace's presence to blackmail Renoir against desertion, in the process denying Renoir opportunities to reconnect with his school sweetheart the way he had been able to reconnect with Shadow Jones. But after witnessing a series of extreme emotional meltdowns Raph has with his brother Michelangelo in Chapter 3: Broken Brotherhood - Burden from "Back Then", Chapter 7: The Untimely Clash - Raphael vs. Michelangelo and Chapter 8: The Cowards, and especially after seeing the ways Raph binge-drinks and cuts himself in times of despair in Chapter 9: Deeper in the Abyss, Renoir guiltily accepts the role of Raphael's anchor, and finally willingly submits to his authority as ninja master. Renoir learns that Raphael has indeed come to love Renoir like family—dysfunctional abusiveness and all. Raph finally accepts Renoir is Augustus in Chapter 11: A Prelude to..., around the same time Raph's charade with Davianna disintegrates, in the process breaking the blackmail. In Chapter 13: Back into the Shadows, Raph loves Renoir enough to let him be free to choose his own life, but still commands Renoir to honor his promises to other people. Raph gives Renoir a meaningful Christmas gift—a pair of tonfas. After Christmas, the relationship between master and student largely stabilizes into one of mutual respect, though still full of mutual antagonism.
The first adult humans to accept Renoir as Augustus Amherst. Augustus has already known them for years as the parents of his childhood friend Shadow Jones, but doesn't learn their association with mutant turtles until after Renoir himself turns into one. The Joneses become precious adult human anchors in Renoir's life, even inviting him to their Christmas party. But they caution Renoir that his own parents, the Amhersts, are not experienced with the paranormal world of mutants, and are not likely to accept Renoir even with irrefutable proof of his identity. In Chapter 10: Rational Voice? Enter Casey and April!!!, when Casey learns that Raphael has taken in Renoir as a student, the first thing he does is haze Renoir, forcing him to binge-drink beer after beer until he vomits.
One of Augustus' most trusted childhood friends. When they were growing up, Shadow would use her fighting skills to protect Augustus from bullies, but would also just as readily beat and punish Augustus for his lecherous acts. Since Shadow grew up with three mutant turtle uncles, mutants per se do not scare her. Still, the first time she and Davianna Wallace witness the mutant Renoir sitting in Augustus' human remains, she assumes the turtle has just killed and eaten their friend, and is partially responsible for perpetuating this early report of Augustus' killing by a mutant, which has made Renoir and the other mutants even more publicly feared than they already were. But she is also later the first human to accept Renoir's identity as Augustus, becoming his most important human friend and contact in the first few months after his transformation, providing a familiar human anchor to help him adjust to his new life. It is through Shadow that Renoir first becomes acquainted with her uncle Michelangelo Hamato, and both Shadow and Uncle Mikey teach Renoir more about the secret history of the Hamato-Jones Family. Renoir and Shadow have a heated quarrel in Chapter 9: Deeper in the Abyss after Renoir intentionally crushes Master Raphael's spirits, causing a rift in their friendship that leads to yet another quarrel when they meet again in Chapter 11: A Prelude to.... But Renoir saves Shadow's life from drowning in Chapter 12: ...The Crimson Christmas after Eikichi Gotoh and his renegade NYC Foot Ninja have brutally beaten her and left her for dead. The two finish mending their friendship in Chapter 17: Between Cops and Ninjas.
Renoir first meets Nobody in Chapter 18: A Little Deeper in Donatello's World on a rooftop. Renoir confuses Nobody for a (NYC) Foot Ninja, and Nobody confuses Renoir for one of the Hamato brothers and demands Renoir take him to see Leonardo. After finally realizing they have never met, the two introduce themselves and explain each other's affiliation to the other turtles. But when Nobody realizes the Renoir is the wild mutant who killed Augustus Amherst, he tries to apprehend Renoir, but Renoir tells Nobody that he is the real Augustus Amherst, and can prove it. In Chapter 19: Fragments of Truth Inside His Mind, Renoir returns with an obscure legal document—a restraining order that Shadow Jones had once filed against him. Nobody explains to Renoir that the proof was irrelevant—only whether Renoir would kill another human if given a chance, so that he could be caught in the act. Renoir is furious that Nobody gambled his sister Carole's life on this hypothesis and refuses to help him. In Chapter 22: The Witch-Hunt of a Bloodline, Renoir meets Nobody again after following Leonardo at night. Leo's dark side has taken control and he is attacking Nobody and Foot Clan alike, leading Renoir to accuse Nobody of lying about not being in the Foot Clan. After Leo temporarily escapes, Nobody confronts Renoir, trying to assure him he would be dead if Nobody was actually a Foot Ninja. Later, when Leo's good side reasserts itself, he tells Renoir that Nobody is an ally of the turtles.
Renoir's dearest friend since childhood and his primary love interest. Augustus met Davianna soon after she was adopted and moved to Brooklyn from Japan. Initially not speaking any English, Davianna used to be picked on at school, and Augustus would come to her aid. The two children became emotionally close, even as Augustus solidified his reputation as a womanizing pervert. Augustus was chivalrous with Davianna, and promised her he would never kiss her until her 18th birthday, even if she were to ask him. Davianna and Shadow Jones witness Augustus' horrific "death" in Chapter 1: Enter the Renoir, and Renoir doesn't get a chance to meet her again until Chapter 4: Watch Out! Business with the Purple Dragons!, when he, Shadow and Raphael Hamato rescue her from Erica and the Purple Dragons. Shadow informs Davianna that Augustus is still alive as a turtle, but Renoir is dismayed when Davianna assumes Master Raphael is her Augustus, and is infuriated when Raph decides to impersonate Augustus in front of her, stealing Renoir's human identity along with his chance of reconnecting with Davianna. Davianna is still introduced to Renoir, but she believes Raph—not Renoir—is "Augustus". Raph, who still does not believe Renoir is Augustus, wants to blackmail Renoir against desertion, but also reasons that Davianna must be in a fragile state of mind to so easily believe Augustus is still alive, and that she needs to believe "Augustus" is a strong heroic figure like Raph, but this does nothing to stop Renoir from trying to reconnect with her. In Chapter 11: A Prelude to..., Renoir and Davianna see each other again in his sister Carole Amherst's hospital room along with Shadow and Raph, but Raph runs off with Davianna before Carole can blow his cover. Raph and Davianna return to the hospital room later, but she is distraught, Raph having blown his own cover, and Davianna runs off upset at both Raph and Shadow. Raph gives Renoir the empty consolation that he finally believes Renoir is Augustus, and had unsuccessfully tried to tell Davianna, also ending Raph's attempts to use Davianna to blackmail Renoir. In Chapter 12: ...The Crimson Christmas, after Eikichi Gotoh abducts Shadow and Davianna outside the hospital, Renoir pursues by jumping buildings, succeeding at rescuing Shadow but not Davianna. In Chapter 13: Back into the Shadows, Renoir participates in a Hamato-Jones family team effort to rescue both Davianna and Master Raphael's brother Michelangelo. As Renoir arrives in Chapter 14: Dogfight!! Up Close and Personal with Remnants of the Foot Clan!, Davianna manages to free herself, but is pursued by an assassin, and Renoir and Davianna cooperate to kill her pursuer. Davianna is deeply upset at having killed a person, but Renoir—not feeling any better about it—assures her that it was necessary to defend themselves. In Chapter 15: And So the Pages Turn..., Renoir and Davianna finally have a moment to talk without anyone else's interference. Renoir reminisces about times when he, Shadow and Davianna were children, and his unique knowledge of his human life's memories unwittingly identifies him to Davianna as Augustus. But now that Renoir finally has Davianna accepting him, he realizes that his identity as Augustus is less important than what Davianna thinks of him, and they both agree to call him "Renoir" from then on. Davianna gives Renoir her magatama pendant as a protective charm before going home. Renoir and Davianna speak again over the phone in Chapter 22: The Witch-Hunt of a Bloodline, finally having a casual moment to reconnect as friends.
- In Mutant Ninja Turtles Gaiden where the four Hamato brothers are now well into their 30s and the title has discarded the word "Teenage", Renoir is now the only teenage mutant ninja turtle.
- It is established in Chapter 1: Enter the Renoir that Raphael named Renoir after the French artist of the same time. A more subtle connection is the character's original human first name Augustus, which is the Latin form of the French name Auguste—the French artist's full name being Pierre-Auguste Renoir.
- Amherst is the name of the most populous town in Hampshire County, Massachusetts. Northampton, the home of Mirage Studios, is the county seat of Hampshire County.
- The turtles have green skin, and the original four Hamato brothers have red, orange, blue and purple bandanas. Renoir's yellow bandana is the last of the six traditional rainbow colors not represented before now.