Caiman (カイマン, Kaiman), or the Magician Killer, is the main protagonist of the manga and anime series. He is a human born in the Hole with an immunity towards magic. He has made it explicitly clear that "Kaiman" was not his actual name, but was given to him by Nikaido after he began suffering from amnesia. His lizard head being the result of a Magic User's curse, his main goal is to seek out the one who cursed him in order to change him back. But, because he can't remember who cursed him, due to his amnesia, Kaiman resorts to clamping his mouth around the head of every Magic User he comes across. He lets them see the "little man" in the back of his head before pulling them back out so he can ask them all the same question: "What did the guy inside my head say?"
He is revealed to be one of the split personalities of Ai Coleman.
Throughout most of the series, Kaiman, true to his moniker, takes on the appearance of a lizard-like entity.
Though Caiman retains his human body, his face and head have changed dramatically due to the effects of a Magic User. He most closely resembles a Paraguayan Caiman Lizard (though some think he looks more like an Iguana), his hair replaced by long and sharp spikes. He sports small crosses over his eyes and wears gas masks most of the time, though he refrains from wearing them later on in the series.
Caiman's design somewhat changes throughout the early chapters of the manga. In the very beginning, Caiman has relatively lanky frame, long limbs, an elongated muzzle and long spikes on the back of his head. In later chapters, Caiman becomes much more muscular, broad-shouldered and burly, with a weightlifter-like physique; his head becomes shorter and snub-nosed, with much shorter spikes, more reminiscent of a head of a lizard. His anime design immediately follows the "burlier" version since Episode 1.
It appears that despite having his head chopped off, he can regenerate it within a few days.
Kaiman usually takes on the personality of someone arrogant and lazy, but deep inside, he's rather kind and cares a lot for his best friend, Nikaido. Even though at times, he can be rude, stubborn, and prone to resolve anything with violence.
But deep down, he only wishes to have his normal head back, eat gyoza, and have more money (in that specific order). And he shows no regard or concern about anything else, except for his friend Nikaido.
He sees Magic Users as scum, killing them on the spot after interrogating them, and showing no remorse afterward. Kaiman hates them, and he even would start a mass slaughter in the middle of their realm to find the one responsible for his head.
He has constant nightmares about his creation and death, causing Kaiman to wake up tired, worried, scared, and trying to forget them. Even if sometimes they have a connection to his past.
He has shown to be a bit absent-minded as during both his jobs he finds himself easily distracted by things.
For two years, Kaiman and Nikaido hunted Magic Users that would invade the Hole. Before taking their lives, Kaiman would engulf their heads in his mouth, allowing a mysterious man inside him to identify the individual. After a short time, he pulls them out to ask what the man said, often resulting in them saying "not the one." Afterward, Kaiman kills them with his knives or other objects. As a result, Kaiman has gained a reputation as the" Magician Killer".
To make a living and to find the Magic User who changed him, Kaiman took on a job at a hospital that specialized in treating victims of Magic Practice working under Dr. Vaux. Easily bored and often slacking on the job, he did chores and asked for money, much to Vaux's annoyance. Once his reputation reached the world of Magic Users upon killing Matsumura and injuring Fujita, a wealthy and powerful figure by the name of En became invested in bringing down the lizard-headed man in Hole murdering his underlings.
While getting photos developed in hopes of seeing the man inside his mouth, Kaiman and Nikaido stumbled upon Ebisu. To their surprise, she attacks them. Her fingers were cut off to stop her from using magic smoke, and her mask ripped off to reveal her face. Despite a moment's hesitation at her young age, Kaiman decided he had no care and then bit down on her head as per usual. However, he was unable to ask his standard question as Fujita appeared to rescue Ebisu, resulting in her face being torn off before escaping.
Later, rumors of a Magic User who could change faces gets spotted in Migimaru-Hole, Kaiman and Nikaido venture to find "The Acupuncturist", locating him in the Kannon of a Thousand Arms club at the bar. Upon realizing he was helping humans and not causing harm, they decide to allow him to live after the interrogation. He attempts to cure Kaiman's lizard head, which at first Kaiman feels an itch in his face only to realize he was shedding, much to Nikaido's disgust.
The Day of the Living Dead, those who died as Magic Practice victims are brought back as zombies by the magic residue found in Hole's rain. Kaiman and Nikaido were killing the resurrected corpses to collect their metal burial identification tags to win a prize for a new meat grinder for Nikaido's restaurant, the Hungry Bug.
However, En had sent out his cleaners, Shin and Noi along with Fujita and Ebisu to deal with Kaiman at the same time, leading to a conflict between the two parties. Kaiman battled Shin. Even though Kaiman is immune to magic, he's outmatched and gets punctured by the sharp end of Shin's hammer. Despite the wound, he managed to stab Shin and bite down on his head, where he met the man inside, leading Shin to realize there was more to Kaiman than they first thought. Tearing off Kaiman's head to free himself, he further was stunned by the face of a man with cross-eye marks grinning at him darkly from within the bloodstream. Nikaido then intervened, revealing herself as a magic user as she summoned a door, dragging Kaiman and his severed head through to escape. With Vaux's aid, they managed to survive, Kaiman's head growing back and the severed one placed in a jar of formalin despite his disgust. Out of curiosity, Kaiman later allows it to be dissected in hopes of finding any potential clues about himself, only for a blackout to occur at the time of the autopsy and the head stolen.
Kaiman signed up to a underground box match against Red Brake in the Noshinto Gong to look for Nikaido after days without seeing her. He found a flyer about the match in her room and knew she tried to win the prize money to pay for the restaurant bills (Kaiman never pays for the large amount of gyozas he eats every day). During the match, Kaiman was strong enough to almost defeat Brake in a few punches but the boxer was empowered by magic with inhuman strength, and almost killed Kaiman. But Nikaido, in the last moment, killed the Magic User who ran the underground box match (also a selling point for Magic User who bought the defeated humans for magic practice), leaving Brake as a fragile old man. Kaiman attaches him to the wall with a single punch. Later, he scolds Nikaido for taking the prize money (because it was dirty money made by human slavery), only for her to scold him for being directly responsible for this mess because he never pays for what he eats. Kaiman, ashamed of this, only agrees with her. Chapter 11
During a trip on New Year's night, Vaux asked him and Nikaido to go to the house of an old friend of his. They got lost for hours in the huge mansion, warped by magic. They finally gave up and had their new year's dinner in the kitchen room, where they found Prof. Kasukabe, an old scientist who researched Magic Users. He studies the corpses of sorcerers killed by Kaiman and Nikaido. After a weird meeting, the Professor explained to them his research, and Kaiman chooses to go to the Magic Users Realm to track down the sorcerer responsible for his head, using an artificial door that Kasukabe made using the sorcerer's corpses. Chapter 13
Going to the Magic User World
Before going, the professor gave them a guide about the sorcerers' culture, disguises (both with a bunny theme), and enough magic smoke spray to return when they did. Immediately after they pass through the door, in the Magic User realm, Kaiman planned to slaughter every single sorcerer they could find until they get the one who cursed him, Nikaido told him to stop it, and only kill people in places with no crowds.
They spend a couple of days living in the apartment of a taxi driver, Magic User, who he killed in the city. Kaiman was disgusted by the weird way the sorcerers live, going into a restaurant, he tried a strange drink and got sick. He passed out in the restaurant bathroom and has a horrible nightmare. However, he makes a discovery and remembers a name, Risu. After that, he woke up, flushed the toilet were he barfed and was almost burned by it, (a toilet directly connected to hell, which Kaiman found stupid and labeled the Magic Users as crazy weirdos). Having that sudden spur of memory, he told Nikaido that they needed to find the man called Risu, as that was the only link he had with his past. They had to leave the sorcerer's realm after Nikaido failed to kidnap Risu, and headed to Hole using a smoke spray that Kasukabe gave to them so that Nikaido could have surgery for the mushroom her back (an effect of En's magic).
Back to Hole, Questioning his choices
Back in Hole, Kaiman carries his friend to The Hospital to let Dr. Vaux and Prof. Kasukabe operate her. He tries to help them while they are working and gives them some tea later, he tries to cook some gyozas while vaguely listening to the Professor talk about the effects of the rain on Magic Users. He doesn't pay too much attention, kicking the door to bring Nikaido's dinner, charcoal-like gyoza with raw garnish inside, nevertheless she still eats them.
Vaux and Kasukabe ask the lizard head what happened to his friend to have so many wounds aside from the big mushroom in her back, and shows a little card they found in her clothes. The Professor explains that the Devil made that, and only high-class magic users have them. Kaiman stops him, knowing where this is going, and the doctors explain to him that they operated on Nikaido with their own hands, her physiology is different than theirs, and she is actually a Magic User. At that moment, Kaiman hears a scream and runs to his friend's room to find she is gone. They quickly jump to the streets to chase after whoever kidnapped her, thinking how it could be possible that Nikaido didn't put up a fight and got captured so quickly, remembering Kasukabe's explanation earlier of how rain weakens sorcerers.
The lizard head chases them to the sewers, where he finds a giant mutant cockroach blocking the way. Kaiman engages in a fight with the creature, but he can't lay a scratch on them, and he gets easily overpowered. Even having part of his arm ripped apart, thinking there is no use to fight the monster, Kaiman escapes while the cockroach eats the piece of his flesh. Finding a door and the end of the corridor, he sees Nikaido wounded on the floor and the mysterious man yelling about how she "Doesn't have a pearl". Kaiman is about to kill him when he calls "Jonson", the giant cockroach from earlier, and restrains Kaiman on the floor. In contrast, the man talks about how he can become a Magic User by using "Black Pearls", nothing more than human bodily waste as Kaiman yells at him. The man is about to gouge the Lizard head body when his legs are chopped and fed to Jonson to get out of the room, he bleeds to death while telling Kaiman that he saw him before his head was transformed. His friend was there too, Vaux and Kasukabe help Kaiman with Nikaido in his back, leaving to the hospital once again.
In the Hungry Bug, Nikaido prepares some gyozas for Kaiman when 13, a recurring customer of the restaurant comes to eat some gyozas (Kaiman is automatically pissed about this, believing he wants to eats his precious gyozas), Vaux also appears sulking about how they are unable to play against the Sharks (the Heiwa Clinic baseball team) unless they find another player, 13 enrolls in the team. Nikaido and Kaiman are ready to play. But Vaux is also concerned about how difficult it is to finish a match thanks to Kaiman's hard way to play, knocking unconscious everyone last year, leaving the match suspended.
Prof. Kasukabe introduces another member of the team to Kaiman and Nikaido, Jonson. The Professor found the giant cockroach, and he experimented with the creature making it docile and even teaching him to speak (only able to yell Shocking!) Kaiman is really disturbed by this. Suss (Vaux younger brother) and his friend Kink appear too to prepare the team. 13 asks Kaiman what kind of relationship he has with Nikaido. The lizard head replies that they are friends, 13 mentions if he doesn't mind if he tries to go with her, and Kaiman says he can always try. During the baseball match, Kaiman is really pissed for some reason and during his turn at the bat swings so hard that scores a home run and destroys a Magic User's corpse from the torture square in the process. The match is suspended thanks to Nikaido. During his turn to the bat, he knockouts the clinic director with a ball directly in the face.
Kaiman stayed in Hole until the nightmares returned. Now more painful and real than ever thanks to his stay in the Magic Users Realm, wondering about Risu, the only person he remembers back there, thinking how much he can remember if he goes back there again. Nikaido asks him if he wants to eat some more. And looking at her back, still recovering from the surgery to remove the mushroom from her back, Kaiman understands that he cannot let her get involved any further in his quest to find his past. Thus, leaving the hungry bug and telling her that he is going to work. He wonders if she would recognize him the next time they met, believing he is going to look different, saying goodbye in his mind, and telling her that she is his only friend, regardless of whether she is a Magic User. The next day in The Hospital Nikaido appears agitated and asks him where is Kaiman, the Professor explains that he appeared yesterday to use the Magic Door to the sorcerers' realm, shocked, she realized that Kaiman went back there without her.
Back to the sorcerers world
In the Magic User's, Realm Kaiman met Fukuyama, a Magic User bullied and almost killed in the streets. Kaiman beats one of the Magic users, and the other one was killed by Tanba, Fukuyama's Boss. Grateful for saving his employee, Tanba hired Kaiman as his brute to work in his Restaurant. Living to anyone's expectation, Kaiman was lazy and usually ate Tanba's meat bags (the restaurant's main dish) and then got beaten up by Tanba for doing so (so far, the only character in the manga able to subdue Kaiman and even make him cry).
Kaiman sneaked in En's Mansion to look for clues about him or his past. But Tanba finds Kaiman and beats him up again. After that, spoiled the lizard head with money for some food in the festival, angering the boss even more.
Without knowing, he indirectly saved Shin and Noi from Yaku and Baku, magic users who kidnapped the cleaners for the blue night, with Fukuyama's help, they killed both leaving the mansion and the cleaners safe.
Unable to sleep, thanks to some recurring nightmares, Kaiman went to Kesber Park again to ease his head. Worrying about his employee, Tanba talked with Kaiman, asking what was going on, and forcing him to accept his help with whatever he needed, when Kaiman explained the situation. The need to find The Cross-Eyes, his boss knew exactly what to do.
He delivered the last meal to a prisoner in Hell's Prison, a regular customer in the cross-eyes that recognized the man inside Kaiman's mouth, as Risu, Confused and angry, he tried to understand the meaning of all that. Still, it was too late, and Shimizu was sucked straight to Hell, and along with it, almost Kaiman and the Tanba crew were sucked to if it wasn't for the timely help of a Devil.
Kaiman was approached by Asu, a Devil friend of Nikaido that told him to rescue her, finding out that En kidnapped Nikaido (tracking the magic used on her back, and incarcerate Dr. Vaux, 13, Jonson and Prof. Kasukabe in the process).
Kaiman Crafted a ridiculous suit and went with the name of Pieman, the recently married wife of Tanba. She gave her figure and her life to the meatbags (Tanba was really pissed of about all that but couldn't do anything about it at that point). Tanba fired Kaiman so he could go to rescue his friend, promising he would go back for his money (even though Tanba wasn't going to pay him anything).
He fought a brainwashed Nikaido until both fell in the catacombs of the Devil Church. Nikaido finally regained consciousness when her contract with En was removed (forcefully by stabbing her in the back) by Kaiman (briefly dominated by Kai's inner urges to kill powerful magic users). They were helped by Asu, to escape as far as they could from En so the contract inside her would not regenerate again, and using Chota (one of the En Family Members) as a decoy by morphing him into a replica of Nikaido to fool En to not look for the original.
After a warm reconciliation and promising each other to watch the other back, the still cross-dressed Kaiman told Nikaido they needed to go to Berith. It's the city where Risu, they found out that Asu sent them to Mastema, a town far away from En's Mansion, nagged for being too far away from everything. They stumbled with Natsuki, a newly enrolled Cross-Eyes girl that took Kaiman as her superior thanks to the crosses in his eyes and accompanied them to her town, where they stole some clothes. The young Cross-Eyes was deceived by her superior Maki, who sold fake Black Powder to third-class addict Magic Users. When he was about to kill her for insubordination, Kaiman teamed up with her to kill Maki and Natsuki, thankful for it tagged with them as a guide to go to Berith.
The trip was long, and they ended in Zaga City, where they found an old abandoned school. Kaiman suddenly felt an intense headache and knew that place triggered some of his memories. Eager to look for answers, he started to dig in the old building, thinking if he was a professor, student, or even a janitor. He found an old archive with files of the students who were there and saw Risu's picture. At that moment, a painful shock, followed by the memories of his past self, talking to Risu, rushed through Kaima's head. He finds out the "truth" about his past, believing that once was a Magic User, he tore the skin out of his face and entered a catatonic state. The crosses in his eyes disappeared too, Natsuki and Nikaido healed his wounds using a medical magic mask and continued their travel to Berith.
They crossed a couple of Magic Users who wanted to kill Nikaido because they believed she was an impersonator of "Lady Nikaido" (Chota was filling the role for her). She had to deal with them all by herself because Kaiman was unable to move, he later told her how scary it was, because he wanted to attack all of them, even her, and couldn't bring himself to do that, becoming even more depressed and quiet. They ended in a luxury hostel and stayed a night in there, Natsuki told them that once they reach the Cross-Eyes headquarters, they would found Risu and the Top Officers. The two would pay for the night in the hostel (The Cross-Eyes top officers were working in there as part-timers to get some more money too). Eventually, they relaxed and got drunk in their room, Natsuki, in particular, even declaring she loved Kaiman and kissed him (more like as part of her playful nature). During the night, Nikaido approached Kaiman, still drinking, but finally, ok. She told him that she wanted him as a co-worker at the Hungry Bug, he was shocked and even told her if she was ok having someone like him as a partner. She happily said yes, because, in another way, she would go bankrupt if Kaiman remained as a customer, making him finally smile.
Kaiman walked in the night wondering if he actually was a Magic User, and even attempting to use some Black Powder Natsuki gave him when they met. Still, at that moment he saw sorcerers with cross-eyes like he used to have, Dokuga and Tetsujo, who was looking for coins in a bending machine. Kaiman could not even grab his knife and was cornered by them, demanding to know who the hell he was and why he was going to attack them, not knowing what to do, he replied "I'm Risu's friend", Dokuga told him if he was Aikawa, and Kaiman was shocked to hear that name. Still, at that moment, the hostel was attacked by En, now knowing about the scam of Asu, he came to kidnap Nikaido once again. In the middle of the chaos, Natsuki found the other Cross-Eyes in there and came along with them to Berith.
Kaiman tried to escape with Nikaido, but En found them and f. Still, Enot his showdown with Kaiman, the lizard head believed he could quickly kill the Magic User because he was immune to magic. Even, En, anticipating this, seeded the air with spores and torn Kaiman from the inside out using his Mushrooms. In his final moments, he was able to smash En's face, enraged. He expelled a considerable amount of smoke which make the mushrooms inside Kaiman grow (at the same time that her doppelgänger killed Ebisu). Thus, dispelling the curse in his head to let Nikaido see him with his real face one more time before dying in her arms, the curse inside him flew away, and his body was retrieved. He was later found by the Magic User Asu.
The "Second Kaiman"
During the events of The Central Department Store, a half turned Devil Nikaido found a disoriented Kaiman on the floor of the building. Eager to hug and salute her lost friend, Nikaido became suspicious immediately about how it could be possible that Kaiman. A being created by a series of convenient events exist in front of her, (now knowing his origins and because The Cross-Eyes Boss is in the building). She hits him demanding to know who he was, with Kaiman only answering in the rude and silly way he is known for.
Noticing the way the spikes of his head were cut. The fact that this Kaiman does not remember anything after the last Day of the Living Dead, she formulated the theory that this is a "New" Kaiman, resurrected using the head torn apart by Shin a year ago and stoled by Curse (know in her room in En's mansion).
Disoriented and overwhelmed by the situation, the devil side of her took control and promised Kaiman to tell all the things he always wanted to know, who cursed his head, who he was, what his face actually looks like, but they needed to find The Store's Kitchen Knife first to get out of the building, making him confused and angry.
Finding The Black House, an entity related to The Devils, Nikaido asked it to send them to Haru, the Devil that had the Knife. After a brief pacific negotiation failed, they attacked Haru. They were taking the Kitchen Knife from her at the cost of Kaiman's life, killed by the Devil's acid breath. Nikaido went back in time to prevent this outcome and leaving the knife to her past self, who gave the Knife to his friend before he banishes to let the time-traveling Nikaido who stopped the previous future exist. Kaiman eventually was possessed the Ai's spirit. This other entity has some control over the warped reality inside the Department Store. Using the Knife to kill Devil Kai (Kaiman was barely able to hold the extremely heavy weapon, but due to his control of the surrounding reality, Ai was able to use it freely). Ai explained that this body is a separate being from both him and Hole, sensing no traces of Hole inside the body, and only having memories of his few years in Hole, his existence is an entirely unexpected outcome to everyone involved. Ai wasn't sure how the result of the battle would affect Kaiman, he remained possessed by the spirit until their arrival to the battle between Magic-Users and the Hole Entity.
Once Ai abandoned Kaiman's body, and the mask of Aikawa dissolved from his head, Kaiman woke up disoriented. Not understanding where he was or what was happening, only to find an almost fully Devil transformed Nikaido in a mushroom suit, Kaiman Couldn't believe any of that. Chapter 146
Kaiman lent the store's kitchen knife to Risu to strike the final slash on Kai's body (now possessed by Ai spirit) the lizard head asked who he was, Risu replied: "For you, a nobody". Once the last head was cut, Kai emerged once more for the final laugh before the room became dark. Acid started to flow to our characters' feet, and after screams and call for help, a creature came from the now-empty lake of refuse, Chidaruma declared that all the people inside the store died, and went to receive the creature, he named it, Hole.
Kaiman woke up inside a strange place, and with him, Nikaido, in her normal form completely naked, he started to talk about how a bulky man was pretending to be her and to put some clothes on. She explains that they are now inside her, and that was the only way to save him, he looks through some holes and spots Kawajiri on the floor. Still, not understanding anything, he almost drops the kitchen knife. This infuriates Nikaido and kicks him out of her body, outside, he finds out that Kawajiri saved them from teleporting them to the black house. Still, he was only able to grab Nikaido (with the lizard head inside), so he could not save Risu.
Nikaido started the final phase of transformation, becoming a full devil (the process was quite disturbing, and Kaiman was quite scared to look at her). After finding out that Store, the creature from where the knife comes from, was there with them after demote all the devils inside the house back to magic users, Kaiman was attacked by Zombie Kasukabe. They pursue him until the lizard head had enough and slapped the professor to cut it out.
- It is shown that Aikawa/Kaiman is actually a split personality of Ai Coleman
- In a twisted way, Kaiman, even amnesic, kept doing his previous work (like The Boss), by killing Magic Users indiscriminately, maintaining traits from both, Aikawa's and Kai's personalities.
- Kaiman's head design in chapter 1 is strongly reminiscent of a caiman head, this design was altered almost immediately in future chapters, giving him a more lizard-like head, with a short snout and more human eyes. His body was also altered, from a slim figure to a bulky and heavy muscle appearance.
- It was revealed in an interview by Q Hayashida in 2006. She tends to start every chapter of the manga when Kaiman is present to draw him in his true form, overdrawing his head later. Reference
- For some unexplained reason after Ai left the second Kaiman body the Crosses in his eyes disappeared.
- Kaiman can shed, at least from his lizard head.
- Kaiman is comparatively more violent than Aikawa, his other persona. As Aikawa, he was much calmer, evidently more levelheaded, and would usually avoid fights unless necessary. Kaiman, on the other hand, is more prone to getting into conflict and doesn't stray from killing people, even when the situation does not call for it.