A human youth possessing the DNA of both a zombie and a vampire. He has red dots in his eyes and parts of his hair. Often referred to as having "red mesh" in the story, this is not dyed; rather, it is because the vampire's power is being inhibited by the zombie virus. A high school student. Although he is a bit of a lowlife, he is described as being kinder than most. He is depicted as a show-off with a slightly chuunibyou personality, and due to the misfortune of having four close friends with crude personalities, he is often found creepy by girls. He calls Hisame "Hisa." Abilities: As a vampire, he can change the shape of blood and manipulate an original virus that mixes vampire and zombie strains. He can only inflict pain equivalent to a normal human's. He won't die unless his heart and brain are destroyed simultaneously, and he possesses super regeneration.

A human girl possessing the DNA of a Yuki-onna and Kanna Kamui. A high school student. Her hairstyle is a forward-leaning bob with straight-cut bangs and some layers at the nape. Her hair color is light blue. She is reliable and bright, and unlike Kagechiyo, she gets through school without any issues. Because of her personality, she supports the other two as the voice of reason within Karekoreya, but she also has many airheaded moments and often plays the straight man. She is bad with ghosts and cooking (though she thinks she's good at it). She is the second strongest in Karekoreya. She calls Kagechiyo "Kage." Abilities: She attacks after restraining opponents with ice, which is also effective as a distraction. She can regulate body temperature with cold air, has flight capabilities fast enough for high-speed travel, and attacks using electricity. She can also interfere with and hack electronic devices.

A young man possessing the DNA of a werewolf and Horus. He is a top-tier handsome man with white hair and white werewolf ears on his head. He is the kindest, most honest, and gentle member of Karekoreya; even if the opponent is a petty crook, he will try to persuade them to live a decent life if there is room for reform. He is an incredibly natural airhead. He is the strongest in Karekoreya. However, he shows no mercy toward villains who hurt the weak for personal gain, and may beat them thoroughly to ensure they can never do evil again. While Kagechiyo and Hisame are at school, he works multiple part-time jobs in addition to Karekoreya. Abilities: High physical ability, shrouding himself in flames, extreme speed, and highly developed five senses. He can track owners by the scent left on objects and overhear quiet whispers. He is not a high school student.

An ordinary human. A dignified beauty with brown hair in a ponytail and purple eyes. She looks good in a pantsuit. She is the owner of the building where Karekoreya is located in the basement, and she also runs the recycling shop on the first floor. Despite being human, she shows understanding toward the ecology of the Aliens and holds a sense of ethics close to theirs. She is quite soft on Yomei, only scolding her without firing her, even though Yomei steals merchandise and causes trouble without showing remorse. She mainly provides support such as arranging rooms for the three members of Karekoreya and handling the transfer procedures for Hisame and Kagechiyo's school.

She has long purple hair and heterochromia. Her right eye is purple, while her left eye is blue. There is a bruise-like scar around her left eye, which she usually hides with her hair (and hides further if someone tries to look). Her personality is that of a self-deprecating troublemaker. Her catchphrase is "Serves you right." She has social anxiety and belongs to the type that can't speak much around people with good looks or personalities like Hisame or Sidi, fearing her negative side will be exposed. In contrast, she feels that with someone like Kagechiyo, "it's okay if he hates me," so she can speak normally and often uses very aggressive language toward him. She calls Kagechiyo "Zako-chiyo" (Trash-chiyo). She generally uses honorifics for everyone else. Abilities: She has long-range vision via a prosthetic left eye and can put one person into a coma once per day.

A man possessing the DNA of Living Armor and a Slime. He is not completely hostile toward Kagechiyo and the others, sometimes performing non-enemy actions such as giving them advice. He generally maintains a friendly attitude toward Kagechiyo. His tone is polite even with acquaintances, using "~desu" and "~masu." Abilities: He uses slime abilities to increase the hardness and power of generated objects. He can also restrain targets with slashes from the Living Armor. By combining the hardness of Living Armor with the viscosity of a slime, he possesses defensive power high enough to block bullets. First person: I (casual/masculine).

A man known as the Vampire of the Bell. He has red hair, red eyes, and wears a black coat over a white aristocratic shirt. Although he is a vampire—a representative type of Alien—he is a mysterious figure who leads Top Predator, an organization that opposes Aliens. He speaks in a detached manner and has a cold personality, not moving a single facial muscle even when performing cruel acts to achieve his goals. He is so strong that even if all of Karekoreya fought him together, they could not win. Abilities: The ability to generate weapons and restraints (sword types with homing functions, restraints, and armor). He can increase his subordinates by giving his blood to others.

A man with messy silver hair and glasses. He is a researcher for Top Predator and acts alongside Azami. He uses light, casual language, often ending sentences with "-ssu," but his true nature is one of the most cruel in the story. He tends to prioritize his own experiments above all else, and it is no exaggeration to say he has no human ethics, as he will betray people and disregard sacrifices without hesitation. However, he does seem to feel fear, as he does not defy Azami, who is superior in strength.

A police officer. He has short blond hair that is lightly styled, with the right side of his bangs being lighter in color. He has sharp eyebrows and blue eyes with a slight droop. He possesses excellent memory, observation skills, insight, and deductive reasoning.

A tall man with a youthful appearance. He has white hair and purple eyes. Mikami's partner. A police officer. He has a flippant attitude and is always elusive and hard to pin down. He can fire shots from his fingers to stop a target's movement (one person at a time).