Kosei is a former police officer and First Class Ghoul investigator. He committed suicide in 2016 while suffering from PTSD.

Kosei Waller
Kosei Waller 2
Name Kosei Waller
User /u/Cortico-Throw-Pin
Species Human
Status Deceased
Age 34
Gender Male
Birthday 4/11
Height 6'4" - 193cm
Weight 100kg
Blood Type A+
Affiliations Tokyo Metropolitan Police Department (Formerly)
Kawaguchi Squad (formerly)
Waller Squad (leader)
Ward 7th Ward
Quinque Parashu
Division Waller Squad
Rank First Class Investigator
Image Gallery


Kosei is a bit of an abnormality in central Tokyo. As a half cast between a very large American father, and small (by comparison) Japanese mother, he towers over most in a crowd by at least half a foot. To add to this, he has a rather stocky build, with wide shoulders, a fair amount of muscle, and the slightly shameful evidence of his poor diet.

However most notably, Kosei has a number of scars across the left side of his head, face and arms from second degree burns. They healed years ago, but the mottly covering of skin has a clear sheen to it and looks very out of place when contrasted to the rest of his complexion. Stubble comes and goes in the unburnt areas, depending on if he felt like shaving that morning or not. His brown hair is usually kept short at the sides, and slightly spiked at the front, just by manner of how it looks when he wakes up.

As a junior investigator, he will wear a disheveled suit and tie most of the time, maybe with an overcoat if it's a bit chilly out. Out of work, he prefers to wear simple hoodies and jeans, even if it does earn him a few comments about trying to act younger than he really is.


From how he normally presents himself, one would be forgiven for thinking of Kosei as the lazy, laid back type. This may be true in some regards, but he's normally quite dependable and conscientious when it comes to work or dealing with others. If given the chance, Kosei can be very generous with both his time and resources, and is generally good at empathizing with others. To add to the latter skill, he's studied Psychology a fair bit, and so will often have deeper insights into someone's state of mind or moods. He rarely offers serious advice, unless faced with a situation that really calls for it. Instead, he prefers to lighten the mood by cracking off base jokes and making silly observations.

As an odd contrast, Kosei can be rather judgmental of others. Whether this be in regards to their behaviour, choices or performance. He's not the most patient of people, and really doesn't like to put up with those who really are a bit too lazy for the job they've taken. Another thing, and to be blunt, Kosei lies a fair bit. It can be very hard to pry the full truth of things out from him, as he'll often twist the truth or tell an outright lie. Kosei doesn't do this out of pure malice, more that it can just suit his needs a bit better, or serve to cover up things he doesn't want to get into with prying individuals.

Kosei has no special prejudice towards Ghouls. At least not one that any member of the public doesn't also have. He sees them as murderers, just like human killers, and would like to see them punished for their crimes. At the same time, he's not an advocate of outright killing them for just being what they are, and would rather just imprison them. Some of the attitudes of the more scarred investigators are off putting to him, and he tries to socialize more with those that are older and less zealous.

He wouldn't consider himself a coward, and by the standards of many he's not at all. However in the situations that Ghoul Investigators often find themselves, Kosei has yet to find a way to completely steel his nerves and face death head on. In his first few encounters with them, the astounding strength and speed of Ghouls froze him with shock. He's been getting better, but has a ways to go before he's as accustomed to the role of the warrior, as he is to that of the detective.

He has quite the fondness for animals, especially small and furry mammals. At home he has two Sakhalin Huskies named Benson and Raff who he babies to no end. He doesn't normally tell others about that... His taste in music leans towards older forms of Jazz, but really he can find most things enjoyable as long as it's not too 'pop'y.


Kosei was born out in a fairly boring city on the edge of Tokyo proper. His father, Gerald Waller was an expat from the USA, over there to try and get away from a complex and tiresome situation with his ex-wife. He worked as a nurse, which is where he met his second wife, Yumi Sano. They would work together for a few years until Yumi asked him out. Up until that point, Gerald hadn’t really considered that kind of relationship. Paying out child support was still a constant and painful reminder of his previous mistakes. That being so, things progressed fairly quickly from there, and Kosei was born a month or so after they were married, just a year after the onset of their relationship.

Things were good for a few years following that. Yumi stopped work to look after Kosei, and Gerald got a few promotions to the senior nursing staff in a local hospital. Sadly enough, it wouldn’t last. Just when young Kosei was just about old enough to have built ties to his father, his parent’s relationship began to fracture. For a while he was subjected to the shouting and the fights, which all seemed very senseless to him. The concept of alcoholism was lost on him at this age.

Unsurprisingly, his mother filed for divorce, and his father left to move city again. His mother was absolutely devastated, despite having been the one who filed for divorce. Gerald had been the only man she’d ever opened up that much to, and she doubted her ability to find anyone else. She’d be right too, even if it was self fulfilling. Yumi fell into a minor but constant depression, mainly only holding on from the edge for her young son, who was only seven at this point in time.

The rest of Kosei’s childhood wasn’t too great, but he got by. He never met his father again, and the only sign they really had that he was alive was the variable flow of monetary support. That didn’t really bother him after a few years though. Well, it at least wasn’t a constant source of dismay. He still had pangs of longing when seeing others with their parents or at times when it would have been helpful to have a fatherly figure.

Throughout school Kosei sort of blended into the background. He remained quite introverted, and even though he grew into quite a large guy, stayed away from sports clubs like wrestling, rugby or basketball. There was a small group of guys he was friendly with, but they were mostly the type to drop out and not do much with their lives. He maintained a grade position around about the class average, not lagging behind, but not doing exceptionally well either.

It wasn’t until university that Kosei finally began to come out of his shell a bit more. The setting, and sharing similar interests to those in his class helped a lot in that regard. Just as he was starting to get along well, Kosei received a call from the police, informing him that his mother had been stabbed during a mugging gone wrong. Yumi didn’t die right away, but after about a week of being in the intensive care ward, she passed away. The funeral was small and quick, only including fifteen people or so. Kosei didn’t even try to contact his father.

Understandably, Kosei was extremely distraught both leading up to and after her death. He got through his first year exams with special consideration marks and took a long while off from social contact.

In second year, he swapped majors from a bachelor of commerce to a bachelor of arts, majoring in criminal psychology. The move was motivated mostly by his mother’s passing, and the cause of her death. He wanted to do something more useful with his life, and help people who’d been in his position.

After graduating, he tried to get work as a police detective, but was turned away at most every opportunity in favor of someone more qualified. He was told that if he wanted the position, he’d have to work his way up from the ground. So, that was just what he did. A year of police college later, and Kosei was serving as an officer of the law in the seventh ward. He was 24 here, but his career would be stagnant for the next decade. Certainly, he progressed within the force itself, but was never offered a position as an investigator, despite multiple applications.

At 27, Kosei met Aiya. He’d had partners in the past, but she was the first that he utterly fell for. She worked as an engineer in a local munitions factory, so they didn’t really share much in common career wise, but both shared a plethora of hobbies, including volunteering at the local animal shelter.

Neither wanted to rush into things, as Kosei’s parents had, so only got married after three years, and never chose to have children. On the surface, things seemed great really. His career might not have been progressing as he’d like, but surely meeting Aiya proved to be a stroke of luck. Well, not quite. After they were married, the relationship deteriorated. Aiya put extra pressure on Kosei to get a higher position as an investigator so she could quit her job. Both began to spend more and more time apart and all sense of intimacy between the two died in short sucession.

Things continued like this for the next few years, until Kosei found Aiya’s phone left on the kitchen counter. It wasn’t locked. He couldn’t help but be curious. Perhaps he shouldn’t have been. Inside was provisional evidence that she’d been cheating on him with other men. More than once. Further investigation only confirmed his hypothesis. He thought he should be upset. Angry even. Oddly enough though he didn’t really care. In fact, he found himself wanting to confront her as soon as possible, so that he could just end the relationship, finally.

Under the guise of bringing Aiya her phone, and flashing his badge to get past security, Kosei slipped into the factory. He didn’t intend to make a scene, but couldn’t put something like this off until she arrived home.

Before he could get to her office, alarms sounded in the building and emergency lighting flicked into place. Explosions could be heard coming from the factory floor, and the temperature began to rise. In a panic, Kosei began to run to Aiya’s office. Perhaps it was out of a sense of duty, or his feelings hadn’t truly dissipated, but he felt like he had to make sure she was okay. Half way there, there were a few more explosions and he turned the corner to see an inferno blocking his path. Smoke was starting to fill the building, and his lungs felt like they were about to burst. Knowing a lost cause, Kosei turned about to run out, but tripped on a fallen chair and hit his head on a table.

When he awoke, a nurse was standing over him, removing his bandages so that they could be replaced. She took back in shock a bit when he opened his eyes, and immediately pressed the ‘help’ button on the wall. Still thinking he was in a burning building, Kosei began to thrash about and cry out in pain from his burns. He didn’t know what it was at the time, but a friend from work had been sitting next to him, and now held him down on the bed to calm him while the nurse rushed off to get help.

Next next few days passed in a bit of a blur due to the painkillers and always being in bed. He could remember being told that his wife had passed, and not feeling as sad as was appropriate. He remembered a few friends coming in to see how he was doing, and the medical staff going back and forth. He was considered stable a week later.

It took Kosei a while to piece all of what had happened together. He wasn’t able to work with his injuries, so spent most of his time at home just thinking. Thinking about life, his previous marriage, his mother, even his father. One could probably equate it to an existential crisis of sorts, except this lasted quite a while.

Once he was back in good health, he got a call from a friend in the force. It was about applying for another position as an investigator, but not the kind he had originally imagined.

For personal reasons, he decided to take the leap, and found his application to the training program was successful. After a couple of months at the Ghoul Countermeasures Training Center, he was taken aside with a few others. They were told, without reason or space for argument, that they were moving to the CCG’s Academy. At that time, he’d only assumed that a ‘Ghoul investigator’ was a mere rank up from ‘Bureau investigator’. If he were to be put in that position now, he probably would have refused outright, even at the cost of his potential job.

Regardless, he got through the academy alright, keeping the trend of remaining as inconspicuous as possible, and staying at the middle of the class. It was a bit like being back at high school really. Especially with all of the young kids. Most days he regretted the move, and doubted if he’d even be suited for the position. That line of thought is still with him today.

Once graduating, Kosei was placed into Kawaguchi Squad as a 2nd Rank Investigator, and his story continues from there.

Powers and AbilitiesEdit

High strength: Due to having the build he does, Kosei is no slouch when it comes to his strength. It could be better, but relative to most others, he's quite powerful. This allows him to wield a Koukaku quinque relatively effectively. However, he's still outclassed by the vast majority of ghouls.

Explosive speed: This is actually an asset that he finds quite useful in the field. Most don't expect him to be able to move at a pace if needed, so will underestimate how fast he can actually move. Granted, he can't keep it up for long, but in the heat of the moment, it helps a lot.

Skilled detective: Having spent many, many years of his life studying and applying the skills needed to be a detective, Kosei found he fits right into the investigation role of being a 'Ghoul investigator'. He's quite good at finding motive and placing himself in the suspect's position, on top of the day to day investigative techniques.


Strengths: Kosei is surprisingly fast for someone of his build, something that often catches his opponents off guard. As you would assume, he's also stronger than most. Not on the level of a ghoul, but strong nevertheless. Before his illness, he was very good at staying calm in a fight, and tried to assess the situation as best he can, without just rushing in willy nilly. He would also consider his ability to diffuse tension filled situations a strength, even if it doesn't directly serve him in combat itself.
Weaknesses: Not entering the CCG early in his life, and spending most of his time studying or at a desk, Kosei really isn't all too fit. He's able to pass the police fitness checks alright, but to no exceptional degree. Two kilometers or so and he's puffed. On top of this, Kosei's also never had much combat experience. Let alone experience fighting Ghouls. His instinctual reactions are rusty and don't serve him well when it's a do or die situation. Most experienced in fighting would be able to overpower him in a proper one on one fight.



Kosei Quinque

Name: Parashu

Type: Koukaku

Status: In service

Appearance: Staff with a long and thick blade running down most of it's length. 3 ft long in total. There is a blue hue to the quinque metal, and there are s number of perforations along the non-cutting edge.

Strengths: Durable and sharp, Kosei is able to use it for both a strong defence and powerful offence. The wide blade gives good coverage from light range attacks, and if given the opportunity, it's weight allows for him to deal devastating blows

Weaknesses: As is common to all Koukaku, the blade is quite heavy and slow to move. Combined with Kosei's non-exceptional reaction times, and he often can't bring it up to defend against opponents who are faster than average. It also has no other special function or effect, meaning there is no potential for surprise or trickery, just brute force.

Mechanics: It is just a large, heavy and sharp blade.


Thread Link Thread Type Thread Description
CCG Newcomers Arc The new wave of initiates are given their final test before entering the CCG proper. Kosei managed to avoid the physical exertion.
No one mentioned the paperwork... Interaction Before being given any proper assignment, Kosei has piles of busy work placed onto him. He decides to take a break, and ends up meeting some interesting characters.
Cargo defence assignment breifing Arc Kosei's portion of the CCG are breifed on an upcoming mission to protect a shipment of Quinque steel and Q-bullets.
Cargo defence assignment Arc Kosei is assigned to a cart with his squad mate, Izumi. The pair fight off a couple of ghouls, but Kosei is defeated, fails the mission, and barely escapes with his life.
An axe, back to the grind Interaction Not yet fully healed from the previous encounter, Kosei is assigned to a serial murder case with fellow Investigator Kristof Brandt. The harrowing investigation affected both men deeply.
Wintertide - OEC encounter Arc Soon after their investigation, Kosei and Kristof are assigned to scout out an area where a Kakuja, the One-Eyed Cat had been sighed. Inadvertently, they run into the Cat. Events proceed from there.
Dinner For Two Interaction Following the fallout of the Hospital Raid, Kosei was assigned to a case in the 21st Ward with his Squadmate Junko Kobayashi. The two were to investigate the activities of a ghoul named 'Crow', and exterminate it.
Bound by Law Interaction In the middle of the Crow Investigation, Kosei responds to a ghoul alert in the 20th Ward.
Hospitable Hospitals Interaction Following the Crow Investigation, and after the majority of his recovery, Kosei begins to pay visists to his partner Kristof, as the giant recovers from his own brushes with ghouls. While Kristof was in his medially enduced coma, Kosei would often confide in him, and use it as a way to vent his feelings of guilt, fear and stress that'd been building up over his short time as an Investigator. He also talked about killing Crow.
Mania and Dementia Interaction One of Kosei's old friend from university ropes him into talking at a seminar on the psychology of ghouls. While he's not terribly enthused, and not in the proper mind set, he puts on the persona of 'Investigator Waller', and attends. His speech isn't particularly fantastic, but he does end up speaking to some enthusiastic and bright students.
Eye for an Eye-CCG Arc Kosei attends the briefing on an upcoming raid on Aogiri's suspected HQ. The gravity of it all forces him to have a panic attack, and he's forced to relive his past experiences.
Eye for an Eye-Aogiri Raid Arc Despite his breakdown, Kosei is forced by duty to attend the battle. He ends up confronting a young ghoul, and attempts to arrest him. At the same time, he's battling just as hard with his mental demons. This does not go well for Kosei, and he's left in a critical condition. Were it not for the ghoul's mercy, and the heroics of a certain Investigator, Kosei would not have lived to see the end of that battle.
Eye for an Eye-CCG wrap up Arc After surviving the ordeal at the Aogiri base, and spending a month recovering in hospital, Kosei attends a promotion ceremony and after party. Surprisingly, he finds himself promoted to a senior First Class investigator. In the face of this, Kosei talks to his former Squad mate Izumi Okazaki about training him to be a better combatant.
Waller's Walls Interaction With his promotion to a First Class investigator, Kosei was tasked with taking on a squad of investigators. He also moved offices to accommodate this change. He meets his two new initiates, and hashes out their roles along with Joseph "Seph" Winters, his new second in command.
Sonnenlicht Investigation/Battle Kristof Brandt, Kosei's old partner and closest friend, has gone rogue for the sake of his adoptive ghoul daughter. Kosei and his new squad are tasked with tracking him down, arresting him, and exterminating the ghoul. They soon find that Kristof is tied up in much more than simply sheltering a ghoul, and Waller Squad is set to contend with the Aogiri leader 'Smiles'.
Treatment One Shot After the ordeal with Kristof, Kosei decides that it's time he received consistent treatment for his mental illness. This was the one appointment he attended.
Candlelight-Assignment Arc Waller squad are given a new assignment, on top of their current ones. They were tasked with investigating the attack on an idol concert.
Candlelight-The Disappearance of a Star Manga Arc Waller squad get stuck into the investigation. They're eventually led to interview Jack, otherwise known as 'Smiles', now in custody due to their prior meeting. Kosei finds this troubling, and not much is learnt.
Hamadaaaaaa Interaction Kenji is an especially energetic new initiate assigned to Kosei's squad. This is their first meeting.
Candlelight-The Conflict Arc The investigation leads Waller Squad to the Aogiri base that was bombed during the CCG raid. There, they encounter the two seemingly opposed group of ghouls. Kosei runs into a ghoul with he alias of 'Scarecrow', and flees when he is unable to handle the ghoul mentally and physically.
Another day, another case One Shot Two police officers are called to an apartment block, to check up on Kosei. They find him after he had committed suicide by hanging. The accumulation of job stresses and his wavering mental state had lead Kosei to take his own life.


Name Details
Kristof Brandt Quickly after their initial introduction, Kosei and Kristof were thrust into the investigation of a string of brutal ghoul killings. Neither knew the other all too well, but they quickly fell into a solid working partnership. The CCG continued to pair them up on one off assignments, such as investigating the One-Eyed Cat's whereabouts. High pressure and trying situations ensured that the two quickly gained a mutual respect for each other and came to trust each other as partners. Kristof, despite being a very odd man, is still probably Kosei's closest friend in the CCG.

While Kristof was recovering from his fight with Kichirou, and in a coma, Kosei would often use his friend as a way to vent the many demons that plagued him. Due to the Raid and Kosei's own injuries, he did not see his friend till weeks after he'd awoken.

They last met when Kosei had been tasked with tracking down and arresting his old friend. Kosei refused, and used the chaos caused by Jack to allow Kristof to escape.

Junko Kobayashi Despite both being in Kawaguchi squad, Junko and Kosei only talked briefly, up until after the events of the Hospital Raid. The two were paired together to Investigate the 'Crow' case of the 21st Ward. In the ensuring couple of weeks, Kosei came to know Junko quite well. He's astounded at her perceptive ability, and respects her for being such a proficient investigator at such a young age. However, he has yet to push past a great sense of pity for the girl, and all she's had to endure in her short career. He worries that she may be taking on too much, too early in her life, but respects her enough to not intrude on her path. After fighting with her against Crow, he came to trust her in combat, as much as he would Izumi or Kristof.

Junko would go on to help train Kosei in hand to hand combat, as he tried to make up for his deficiencies as an investigator. Unfortunately, he would push Junko away as he progressed further and further into his depression and eventual suicide.

Jiro Horikoshi Jiro accompanied Kosei on one of his impromptu patrols without much of an invitation. During the investigation, the young investigator proceeded to show his incredible ability, along side his astounding lack of tact and common sense. Kosei is fairly certain Jiro has mental issues, and that he should be getting treatment, rather than murdering ghouls for the CCG. He disapproves of Jiro's employment.
Ren Kawaguchi Ren was Kosei's first squad leader. He has never met him.
Izumi Okazaki Izumi is another member of Kawaguchi Squad. The two worked together to defend the train from ghouls, and were partnered up in the same cart. Although Kosei finds the young man to be a bit distant and reserved, he can't deny that he has an astounding talent in his swordsmanship, and puts Investigators like Kosei to shame in terms of combat ability. Were it not for Izumi and his efforts, Kosei likely wouldn't have made it off that train alive. He trusts Izumi greatly, enough that he would go on to ask him to help train him in sword combat. Unfortunately, like with Junko, Kosei would go on to distance himself from Izumi towards the end.
Kichirou Kurosawa Kichirou was a member of Kosei's squad before he was abducted. Kosei had never shared much meaningful interaction with the man, but he had found he liked him more than most around the CCG. When he was taken, Kosei attended his funeral. He does not know that it was Kichirou who was responsible for Kristof nearly being killed.
Joseph "Seph" Winters Seph was Kosei's second in command in Waller Squad. Kosei respected Seph's skills as an investigator, and leaned heavily on him when it came to combat engagements for their squad. The two never had a chance to develop a friendship before Kosei took his own life.
Matsuo Harada Harada was an initate in Kosei's squad. Kosei saw a lot of potential in the young man, and respected his courage, but never got to know him very well.
Jack Conklin Jack, otherwise known as the A rate ghoul 'Smiles', was one of the few people Kosei found he had true hate for. It was discerning for him to learn that Jack had been manipulating Kristof, and to some extent Kosei, from as far back as their first investigation together. Kosei was glad that he at least got to serve Jack justice for all he did to Kristof.




  • His face claim is Dick Gumshoe from Ace Attorney
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