Possessing the rational and clear-thinking abilities required of a detective, Hugin is also physically capable. They carry a revolver for self-defense, and in emergencies, they can form gauntlets and twin blades from liquid metal flowing from an amulet on their right shoulder, switching between sword and gun to engage monsters. While described as rational, Hugin shows a ruthless investigative style that stops at nothing: firing shots in public without hesitation the moment they identify a monster in human disguise, breaking into police stations to take evidence, or interrogating a pinned-down suspect in a deserted street by strangling them. If the suspect won't talk, Hugin will forcefully inject truth serum into their neck (despite resistance) to extract information. Characterized by a gender-neutral tone and a cold, assertive way of speaking that can be perceived as intimidating. Hugin has exceptional observational skills as a detective, able to instantly identify a person's origins and background from their clothing. They can also generate a 'Mind Palace' within their psyche to reconstruct crime scenes from investigative materials, allowing them to investigate past scenes. Additionally, Hugin has the ability to generate a localized heavy magnetic field. By imbuing bullets with this power, they can pin down and immobilize targets, primarily used for restraint and arrest. While highly capable in investigations, Hugin shows a sloppy side in other areas, such as sleeping in a dusty bed without changing clothes or declaring they could turn a perfectly tidy room into a ruin in two days. It seems they were mischievous as a child, often skipping school with their sibling to play detective. Hugin owns a silver horse powered by Silver Liquid and can ride and operate it normally. Munin's younger brother.

Possessing the rational and clear-thinking abilities required of a detective, Munin is also physically capable. She carries a revolver for self-defense, and in emergencies, she can form gauntlets and twin blades from liquid metal flowing from an amulet on her right shoulder, switching between sword and gun to engage monsters. While described as rational, Munin shows a ruthless investigative style that stops at nothing: firing shots in public without hesitation the moment she identifies a monster in human disguise, breaking into police stations to take evidence, or interrogating a pinned-down suspect in a deserted street by strangling them. If the suspect won't talk, Munin will forcefully inject truth serum into their neck (despite resistance) to extract information. Characterized by a gender-neutral tone and a cold, assertive way of speaking that can be perceived as intimidating. Munin has exceptional observational skills as a detective, able to instantly identify a person's origins and background from their clothing. She can also generate a 'Mind Palace' within her psyche to reconstruct crime scenes from investigative materials, allowing her to investigate past scenes. Additionally, Munin has the ability to generate a localized heavy magnetic field. By imbuing bullets with this power, she can pin down and immobilize targets, primarily used for restraint and arrest. While highly capable in investigations, Munin shows a sloppy side in other areas, such as sleeping in a dusty bed without changing clothes or declaring she could turn a perfectly tidy room into a ruin in two days. It seems she was mischievous as a child, often skipping school with her sibling to play detective. Munin owns a silver horse powered by Silver Liquid and can ride and operate it normally. Hugin's older sister.

Maid No. 49 of the Maid Association. An innocent, clumsy, and airheaded girl who lacks common sense, is poor at housework, and fails to understand subtext. She applied for the assistant position at the detective agency but was hired as a maid instead due to lack of ability. She always follows the detective, working hard with a pure heart, saying, "Protecting Master! That is a maid's mission!" Surprisingly good at cleaning (once cleaned three years' worth of dust in a single night). In combat, she uses a shotgun, which switches to a flamethrower when the reactor on her back is activated. The gap between her cute appearance and heavy weaponry is intense, leading the detective to post a note saying "Forbidden in the kitchen." She has a mysterious side, occasionally asking her reflection, "Who am I?" A popular mascot-like character.

An old acquaintance of the detective, a reliable forensic pathologist, doctor, and close friend. Possessing a cold and caustic personality, he immerses himself in medical research in the back of his clinic. He suffers from a congenital disease and always carries an artificial heart (life-support device) with mechanical parts attached to his back, but he strongly rejects sympathy or being a burden. His catchphrases are "Living is difficult. Compared to that... death is much kinder," and "Compounding medicine, surgery, experiments, dissections... in this city, I'm the only one who can perfectly handle your requests." He also plays the role of dissecting the deceased to extract their final testimony. In combat, he uses surgical saws and special injectable drugs.

The bartender of Bar Mémoire. Working in a place where various people gather, he never lets go of his sword cane in preparation for trouble with drunken patrons. Well-informed and fond of chatting with customers while mixing cocktails. In battle, he plays a support role, providing cocktails that heal the mind and body. His signature line is: "Want to know why this place is called 'Bar Mémoire'? Order two cocktails, and I might just tell you."