Female. Convict No. 999. Alias: The Witch. 156cm. Has a habit of saying "It's playtime!" before fighting enemies. A Special Teacher in the Dandelion Class. As a "witch," she is proficient with all types of weapons. A former legendary assassin with bright brown hair in a ponytail and green eyes. She has a cheerful and clumsy personality. Infamous in the underworld to the point everyone knows her. During combat, she consciously tries to stop herself from smiling while fighting. She speaks politely. In reality, she seems to dislike killing people. 20 years old.

Special Teacher in the Dandelion Class. Convict 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 in the Dandelion Class. Convict No. 829. 153cm. A woman with a calm impression, blue eyes, black bobbed hair, and a yellow hairpin. Her main weapons are bombs and a baseball bat. A capable fighter who pulls her own weight. She has a calm, stoic personality and expresses her emotions clearly. She speaks politely. Since coming to Black Kindergarten, she has become slightly more lively while spending time with Doug and Rita. She was raised as the youngest daughter of the Bradley family, a famous clan of assassins. Rumor has it that wherever Hana passes, only ruins remain. 18 years old.

Special Teacher in the Chrysanthemum Class. Convict No. 225. A handsome man with blonde hair and black eyes, featuring 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 of his class at the police academy and was strong enough to be appointed the youngest head of London's Counter-Terrorism Department. Outwardly stoic and calm, he quietly takes good care of those around him. 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 killer, 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.

Yoshiteru Ikeda. Convict No. 252. 174cm. Special Teacher in the Chrysanthemum Class. Two-toned black and reddish hair. He looks Chinese at first glance but is actually Japanese. He wears a sleep mask with shojo manga-style eye stickers on it. He has an extremely optimistic, bright, and laid-back personality. His main weapons are a shotgun and Dragon's Breath rounds (which turn the shotgun into a flame projector with a 20m range). Thanks to his ammunition, the corpses he leaves behind are always charred. 25 years old.

Sylvia Scott. Convict No. 199. 170cm. Female. Special Teacher in the Chrysanthemum Class. Orange eyes and ivory-grey hair tied up with a claw clip. She plays the "straight man" role and is a tsundere. She actually has a huge weakness for sexy men. She has a great physique. In the past, she worked as a courier transporting 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. Convict No. 411. Teacher in the Violet Class. He wears a yellow teddy bear mascot suit and 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 is calm and stoic but not necessarily silent. 190cm tall. Former high-level professional assassin.

Una Mauri. Convict No. 412. 138cm. 16 years old. The strongest Special Teacher in the Violet Class. An eccentric girl with purple pigtails who speaks only in four-character idioms (Chengyu). Mac translates for her. Because she only uses idioms, it's not immediately obvious, but she has a very foul mouth. (Example: Una: "Furious Rage! Heinous Villainy! Utter Absurdity! Sworn Enemies! Half-Doubt! Lost in a Dream! Unspeakable Nonsense!") Her main weapon is an anti-tank rocket.

Lui Fiore. Male. 24 years old. 185cm. Special Teacher in the Dandelion Class. Former priest and assassin. Main weapon is a chainsaw. A handsome man with blonde hair, tanned skin, and squinting eyes. Raised in a family of priests and assassins, he prayed to God for revenge after 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 began to view her as his savior. He calls Rita his savior from their first meeting and even shares his life story. He speaks politely to everyone and is generally calm and kind.