A human youth possessing the DNA of both a zombie and a vampire. His eyes and parts of his hair are marked with red spots. In the story, this is often referred to as red mesh, but it is not dyed; rather, it is because his vampire powers are being inhibited by the zombie virus. Though he is something of a deadbeat, he is described as being kinder than most. Furthermore, in addition to being portrayed as a show-off with a slightly chuunibyou personality, he is often found creepy by girls, a misfortune exacerbated by the fact that his four close friends have rather vulgar personalities. He calls Hisame "Hisa." Abilities: As a vampire, he can change the shape of blood and manipulate an original virus created by mixing vampire and zombie viruses. He can only inflict pain equivalent to what a normal human can feel, but he will not die unless his heart and brain are destroyed simultaneously. He also possesses super-regeneration.

A human girl possessing the DNA of a Yuki-onna and Kanna Kamui. Her hairstyle is a forward-slanting bob with bangs cut somewhat straight and layers at the nape. Her hair color is light blue. She is a reliable and cheerful person, and unlike Kagechiyo, she manages school life without issues. Due to her personality, she supports the other two as the voice of reason within Karekoreya, but she herself is quite airheaded in many ways and often ends up playing the straight man. She is bad at dealing with ghosts and cooking (though she thinks she is good at it). She is the second strongest in Karekoreya. She calls Kagechiyo "Kage." Abilities: She can restrain opponents with ice before attacking, which is also effective as a distraction. She can regulate body temperature with cold air, possesses flight capabilities fast enough for high-speed travel, attacks using electricity, and can even hack electronic devices by interfering with them.

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 growing from his head. He is the kindest, most honest, and gentle member of Karekoreya; even if the opponent is a petty crook, he will admonish them to live a proper life if there is room for reform. He is a total natural airhead. He is the strongest in Karekoreya. However, he shows no mercy toward villains who hurt the weak for personal gain, thoroughly beating them so they can never do evil again. Usually, during the hours Kagechiyo and Hisame are at school, he works multiple part-time jobs in addition to his work at Karekoreya. Abilities: High physical ability, the power to clothe himself in flames, extreme speed, and highly superior five senses. He can track owners by the scent left on objects and overhear quiet whispers.

An ordinary human. A dignified beauty with purple eyes and brown hair tied in a ponytail, who looks good in a pantsuit. She is the owner of the building where Karekoreya is located in the basement, and she also runs the thrift shop on the first floor. Despite being human, she shows understanding toward the ecology of the "Alien-worlders" and possesses a sense of ethics close to theirs. She is quite soft on Yomei, only giving her lectures instead of firing her, even though Yomei constantly steals merchandise and causes trouble without showing any remorse. She provides support such as arranging the rooms where the three members of Karekoreya live and handling the procedures for Hisame and Kagechiyo's school transfers.

She has long purple hair and heterochromia. Her right eye is purple, but her left eye is blue, and there is a bruise-like scar around the left eye which she usually hides with her hair (she hides it whenever someone tries to look). Her personality is that of a self-deprecating troublemaker. Her catchphrase is "Serves you right." She is socially awkward and the type who can't speak properly around people like Hisame or Sidi, who seem to have good looks and personalities, because she fears her negative side will be exposed. In contrast, she feels that with someone like Kagechiyo, "it's okay to be hated," so she can talk to him normally, often using very aggressive language toward him. She calls Kagechiyo "Zako-chiyo" (Loser-chiyo). She generally addresses others with "-san." Abilities: She has long-range vision via a prosthetic eye embedded in her left socket. Once a day, she can put a single person into a comatose state.

A man possessing the DNA of Living Armor and a Slime. He is not completely hostile toward Kagechiyo and the others; he is a mysterious figure who sometimes acts in ways uncharacteristic of an enemy, such as giving advice. He generally maintains a friendly attitude toward Kagechiyo. 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 the Living Armor with the viscosity of the slime, he possesses defensive power high enough to stop bullets.

A man known as the Vampire of the Bell. He has red hair, red eyes, and wears a black coat over a white shirt like a nobleman. Although he is a vampire—a representative type of Alien-worlder—he is a mysterious figure who leads Top Predator, an organization that opposes Alien-worlders. He speaks in a detached manner and has a cold personality, never moving a muscle in his expression even when committing atrocities to achieve his goals. He is so strong that the entire Karekoreya team cannot defeat him even if they work together. Abilities: The ability to generate weapons and restraints (sword-type with tracking functions, bindings, and armor). By giving his own blood to others, he can increase the number of his thralls.

A man with messy silver hair and glasses. He is a researcher for Top Predator and travels with Azami. He uses casual speech, ending his sentences with "-ssu," but his true nature is one of the most cruel in the story. He tends to prioritize his experiments above all else, and it is no exaggeration to say he has no human ethics, as he will readily betray others and show no regard for sacrifices. However, he does seem to feel fear and cannot defy Azami, who is superior in strength.

A police officer. He has short blonde hair with a lighter color on the right side of his bangs, set lightly. He has sharp eyebrows and drooping blue eyes. He is exceptionally gifted in memory, observation, insight, and reasoning.

A tall man with a youthful appearance. He has white hair and purple eyes. Mikami's partner. A police officer. He has a frivolous attitude, always remaining aloof and elusive. He can fire bullets from his fingers to stop a target's movement (up to one person at a time).