Shiro is the chef of Building 13 and is one bear of a man. He towers over almost every other character. Those unfamiliar with Shiro are always intimidated and frightened by his appearance. Shiro, however, is a very kind and timid individual. It is only through Rock that the depth of Shiro's personality can be understood.

Due to his love of food, Rock really gets along with Shiro, and, as a result, is able to understand his feelings. Like his name suggests, Shiro is a blank slate. But it is due to this facial expression that so poorly portrays his emotions that Shiro is one of the more colorful characters.

"This is my happy face!"

Seitarou is one of the guards of Building 13, the youngest actually. His youth is made extremely evident in his overly sensitive, cry baby nature. Perhaps it's because he is so sensitive; perhaps it's because he's a crybaby; either way, the inmates of Building 13 don't quite respect him. This results in him constantly being bullied by them. After crying to Hajime that they won't obey him, Seitarou feels accomplished, as he finds himself to be doing a better job of keeping them in their cell and well-behaved.

It turns out, that they had simply turned him into their errand boy, having him fetch them comics, games, and food. Because of his age, however, he never realized this and was pleased to no longer be bullied by the inmates. Between his constant crying, seeking approval and respect, and laying down the law when he needs to Seitarou makes himself quite a colorful character.

Despite only truly making his debut towards the end of the season, Elf makes his presence known and proves that having a colorful personality isn't always a good thing. Elf is, in fact, what one would almost definitely call a psychopath. Elf has connections to the mysterious guard with a scar that Jyugo and Musashi have spent their time searching for. He has shown that he is willing to do anything to help progress the research of the guard with a scar.

To this end, he infiltrated Musashi's school, spread rumors about him being an arsonist, and then proceeded to burn down Musashi's house. All to get him locked up so that they could run experiments on him. This psychopathic behavior is further shown when he finally reveals himself and confronts Jyugo.

Throughout the confrontation, he constantly chides Jyugo about how rude he is to have forgotten Elf, all the attacking him in hopes that he uses the weapons in his shackles. The entire situation is made even more strange by the fact that Jyugo constantly feels pain from Elf's attacks, only for the wounds to magically disappear; all the while, Elf continues to taunt him for becoming so weak. Due to Elf being able to dance circles around Jyugo, Elf's demeanor is jovial for the majority of the interaction. That is until Jyugo refers to the guard with a scar as a "bastard."

Immediately, his personality switches and the sinister side that we knew was there all along comes out to the front. He then jumps off the roof of the building because there's no better way to exit after having your way with someone.

Honey is an inmate of building 3 and is the self-proclaimed most beautiful man in Nanba Prison, much to the chagrin of Trois and Kiji, who have also claimed that title for themselves. He is a very calm person but has been shown to have a short temper. This change in temperament is usually represented by a physical appearance. In addition to the physical change, the once cool and calm Honey becomes much more vulgar, very unbecoming of his beauty.

Honey, may be the most beautiful (supposedly) in Nanba Prison, but he's still a guy locked up in a prison without the comfort of a woman. Because of this, like just about any other inmate, he is completely enamored with KAGU-8, the robot daughter of Okina and Kazari Otogi, the head doctor and scientist at Nanba Prison. He relishes the opportunity to see her, often taking the opportunity to ask about the color of her underwear. It's perfectly fine when he does it, when the other guys, especially Trois, show interest and ask other questions about her underwear, however, they're perverts.

Is no one in this prison normal? Yamato is one of the guards of Building 13. Unlike many of the other guards, Yamato is a very happy and carefree person. While Jyugo and the others are trying to escape, Yamato is usually nowhere to be found. This is because either he's managed to lose his way, or he is too busy training to be bothered. If Yamato's not too busy training, he's also probably preoccupied participating in some of the most stereotypical Japanese activities or professing the greatness of Japan.

Yamato is one of the louder and more boisterous characters, always announcing his presence with his loud booming voice, or even a horse through the cell wall, because he is easily one of the most ridiculous characters in a show full of ridiculous characters. One might even say Yamato is also a very KY character, as is he is always smiling, regardless of the situation.

Kiji is the guard of building 3, and thus Honey and Trois. Like Honey and Trois, Kiji is very concerned about his appearance. Kiji professes that he is the most beautiful in Nanba Prison, a statement that is often met with dissent from Honey and Trois, who also make the same claim. Kiji's obsession with beauty doesn't stop with himself, however, as he is constantly judging the beauty of everything: things said to him, the inmates, and even the actions of the other guards. Kiji also shows a preference to other inmates whom he deems beautiful, having a ranking of all the beautiful men of Nanba Prison, and chastising those of lower ranking.

In addition to his constant obsession with beauty, Kiji is constantly (like all of the guards) bickering with the other guards. Of course, he usually takes offense with statements he finds unattractive. Kiji's role as a guard, of course, is related to his concern with beauty, as he sends Honey and Trois to the infirmary to treat the smallest paper cuts the got from playing Hyakunin Isshu, because "Beauty can't be built in a day."

Mitsuru is the voice of Nanba Prison. Literally. He serves as the announcer of the Year End's Tournament, as well as the narrator of the show at times. For this role, it's very necessary to be loud, expressive, and energetic: traits which all apply to Mitsuru. Even when the situation doesn't call for it, and instead needs a more serious tone, Mitsuru can be found bringing a lot of positive energy to the situation. Mitsuru's crazy behavior extends even beyond the actual events of the show, breaking the fourth wall on occasion to explain what's been happening, or even take attention away from the action.

Mitsuru is also one of the few guards who seems to acknowledge the Warden's crush on Hajime. And acknowledge it he does, even if it results in physical punishment. This provides great material as he finds the most outlandish ways of teasing Momoko for her crush, such as taping a picture of Hajime to his face and asking for a kiss.

Real Japanese Ninja?! That's right, Tsukumo's a real Japanese ninja. Much to the disbelief of Jyugo, Tsukumo asserts that he's a real ninja when he joins the guys in Building 13. To prove his authenticity, he is challenged to an escape race. During the race, Tsukumo lets Jyugo do all of the work and steals the victory and praise from Nico, Rock, and Uno. Not only does Tsukumo constantly claim to be a real ninja, but he also constantly proves himself to be a very inept ninja, constantly using ninja tools in the wrong way. Despite this, Nico, Rock and Uno are constantly honored to be in the presence of a "Real Japanese Ninja!"

Eventually, it's explained that Tsukumo is actually an actor, who decided to play the role of a ninja when he was sent to Nanba Prison. The reason he decided to play the role of a ninja? It is explained that Tsukumo is originally from a ninja village, but he was abandoned because he was not skilled in the ninja arts. He was then rescued (or kidnapped) and trained to be an actor, exclusively for roles as a ninja. Despite once being a real ninja, Tsukumo fails at being a ninja in every possible way. But he's a "Real Japanese Ninja!"

Momoko is just about the only female character in Nanbaka and thus Nanba Prison. Momoko's not a prisoner or guard in Nanba Prison, though. In fact, her role goes much more beyond that: She's the warden of Nanba Prison. And to be the warden, and a woman, she must rule the prison with an iron fist. She must instill fear in the hearts of her inmates and guards.

Momoko is feared by nearly all of the guards in Nanba Prison, but she does have one secret and weakness that could cost her the respect of her subordinates: She's hopelessly in love with Hajime. Few guards are aware of her crush on Hajime, but not the extent to which she's crazy about him. Anytime she interacts or sees Hajime she turns into a chibi giddy schoolgirl. Of course, she's the most powerful person in Nanba Prison. Her cheeks reddening as she looks at Hajime. Rage? Her speechlessness in response to Hajime's actions. Rage? The complete switch between the stern warden and hopeless romantic definitely makes Momoko one of the more colorful characters in Nanbaka.

Don't do drugs kids. Or... you could do so many drugs that you become immune to just about every drug known to mankind. That seems to be the route that Nico decided to go with. Despite his immunity to the effects of drugs of all kinds, Nico can still become easily addicted. This addictive personality, however, doesn't extend to only drugs: Nico can also become "infected" by people. If he's exposed to people for too long, he can become affected by people like a drug, explaining why he's able to learn the Kame*meha, Erupting *od Fi*ger, Seki* Ten*ken, and Qigong without any sort of training.

It's not only his relationship with drugs that makes Nico the most colorful character from Nanbaka. Nico is easily the most childlike and innocent inmate in Building 13 and perhaps all of Nanba Prison. It's this childlike nature that makes Nico such an interesting and colorful character. Regardless of the situation, Nico is always cheerful and excited. During the New Year's Tournament, Nico gleefully fought against Upa, all the while begging him to allow him to be his disciple. During this fight, he even took the chance to say all the phrases from his "Things I Always Wanted to Say Ranking." In the rare situation, that Nico is being serious, he immediately returns to his carefree self. Nico's childlike nature is also ever present in his love for video games and anime, and his purely innocent way of always shouting "Hajime-chan!"