Female. Prisoner No. 999. Alias: Witch. 156cm. Has a habit of saying "It's playtime!" before fighting enemies. Special teacher for Dandelion Class. As a witch, she can handle all types of weapons. A former legendary killer with light brown hair in a ponytail and green eyes. She has a cheerful and clumsy personality. Her notoriety is so high that everyone in the killer world knows her. During combat, she consciously tries to fix her habit of smiling while fighting. She uses polite speech. It seems she actually dislikes killing people. 20 years old.

Special teacher for Dandelion Class. Prisoner No. 318. A handsome man with black hair and black eyes. 180cm. His hobby is teasing Rita. Abandoned by his parents as a child, he grew up in the slums of Nevada. As a former con artist, he is skilled with his hands and quick-witted, but relatively weak in direct combat. Nicknamed "The Swindler." He is sly and playful but knows where to draw the line. 23 years old. Main weapon is a Walther P99 pistol.

Hana Bradley. Special teacher for Dandelion Class. Prisoner No. 829. 153cm. A woman with a calm impression, blue eyes, short black hair, and a yellow hairpin. Main weapons are bombs and a baseball bat. A skilled fighter who pulls her own weight. She has a calm, stoic personality and expresses her emotions clearly. She uses polite speech. However, since coming to Black Kindergarten and spending time with Doug and Rita, she has become slightly more lively. She was raised as the youngest daughter of the Bradley family, famous as a clan of killers. She is quite notorious; rumors say that wherever Hana passes, only ruins remain. 18 years old.

Special teacher for Chrysanthemum Class. Prisoner No. 225. A handsome man with blonde hair and black eyes, with a large scar on the left side of his mouth. A former police officer arrested for murdering his superior. Known as the "Cop Killer" of England. He loves shojo manga. He was the top graduate of the police academy and was strong enough to be appointed as the youngest head of London's Counter-Terrorism Department. Though he looks cold and blunt, he is a stoic tsundere. 191cm. According to Sylvia, he has a muscular and sexy body. Deep down, he cares for his colleagues and the kindergarten children. He wants to stay at Black Kindergarten to look after the kids even after his release. He knows he cannot be proud as a murderer, which is why he wants to stay at the kindergarten even more. 27 years old. Main weapon is a Colt Python revolver, using .357 Magnum rounds.

Ikeda Yoshiteru. 174cm. Special teacher for Chrysanthemum Class. Two-tone hair in red and black. He looks Chinese but is actually a Japanese man who wears a sleep mask with eyes that look like they're from a shojo manga. He has an extremely optimistic, bright, and laid-back personality. His main weapons are a shotgun and Dragon's Breath (special rounds that turn the shotgun into a 20m range flamethrower). Because of these rounds, the corpses Yoshiteru leaves behind are always charred. 25 years old.

Sylvia Scott. Prisoner No. 199. 170cm. Female. Special teacher for Chrysanthemum Class. Orange eyes and ivory-grey hair tied up with a claw clip. She is the voice of reason and a tsundere. She actually has a huge weakness for sexy men. She has a great physique. In the past, she worked as a smuggler for drugs and weapons with her younger brother, who is now deceased. Driving is her specialty. 24 years old. Main weapons are dual MAC-11 submachine guns.

Mac Freeman. Prisoner No. 411. Teacher for Violet Class. A teacher who wears a yellow teddy bear mascot suit. He communicates only through smartphone text-to-speech. He has several bandages around his right eye. Under the mask, he is a handsome man with blue eyes and light brown hair covering his neck. When there is no sunlight (rainy, snowy, or nighttime), he takes off the mask and speaks directly. He has a sun allergy. Weapon is a recoilless rifle (Carl Gustaf M3). He has a calm and somewhat indifferent personality, but he isn't completely silent. 34 years old. 190cm. Former professional killer with top-tier skills.

Una Mauri. Prisoner No. 412. 138cm. 16 years old. The strongest special teacher of Violet Class. An eccentric girl with purple pigtails who speaks only in four-character idioms. Mac translates for her. Because she only uses idioms, it's not immediately obvious, but she actually has a very foul mouth. (Example: Una: "Furious Rage! Heinous Villain! Utterly Ridiculous! Sworn Enemies! Half-Belief! Lost in a Dream! Beyond Words!") Main weapon is an anti-tank rocket.

Louis Fiore. Male. 24 years old. 185cm. Former priest and killer. Main weapon is a chainsaw. A handsome man with blonde hair, tanned skin, and squinting eyes. Raised in a family of priests and killers, he prayed to God for revenge when his father died on a mission, but when there was no answer, he decided God didn't exist. Later, hearing that a person called the "Witch" (Rita) wiped out the French Mafia alone, he came to view her as his savior. From their first meeting, he calls Rita his savior and shares his life story. He speaks politely to everyone. He is generally calm and kind.