A 17-year-old with fluffy, curly blonde short hair and beautiful violet eyes. He stands 175cm tall and weighs 58kg. His hobbies include experiments and mechanical repairs; he likes black tea and dislikes dark forests. Born on April 1st. He is fire-attributed, and his symbol is the sun. He is weak to water but is a genius who passed the country's most difficult national certification on his first try. He is generally calm and kind. His tone is detached, as if stating facts, but when speaking to strangers or superiors, he uses a mix of polite and masculine, gentlemanly speech. Once he decides to do something, he won't stop until it's finished. He is kind and composed, honest about his curiosity, but refuses to do things he has no interest in. He is a normal human, not a Demon-possessed. First person: I (casual/masculine). He has a friend named Jack, a kind-hearted doctor who is wind-attributed.

Owl's foster father and a national alchemist of the earth attribute. A gentlemanly man resembling a nobleman with short silver hair, silver eyes, and a monocle on one side. 63 years old. Master of a maid named Hannah and a butler named Ralph.

A girl with long wavy blonde hair and straight-cut bangs. She has red eyes and an inorganic, doll-like appearance. She always wears a dark red hooded cape. Her age is unknown, but there is no doubt she is young.

A man who looks like a youth with a purple stole draped over his shoulders, long silver hair, and golden eyes. Though he is a priest, he has a gaze that is far too sensual. He is a Demon-possessed who has lived for over five hundred years and has been Byron's comrade-in-arms for just as long. First person: I (polite).

A man with beautiful blue-green hair, golden eyes, and tanned skin. He is the owner of the pub "Mistilteinn." The shop's name means the god-killing mistletoe. The pub serves as a cover for the Owl Detective Agency; the first floor is the pub, and the second floor is the agency. Since the agency is designed so that no one can find or enter it without a letter of introduction, there are no signs or markings on the building. He is a fallen angel who has lived since Genesis, not just five hundred years, and is a Demon-possessed. He met Clemens about five hundred years ago, and they became close comrades; they have been together ever since. He speaks with a masculine tone. First person: I (rough/masculine). He is a very good cook.

A fairy-type Demon-possessed who is Owl's partner and assistant. A skilled information broker. He is well-versed in demonic information that is normally unobtainable. The mood maker of the Owl Detective Agency. He loves pranks and has a childish personality. Height 164.5cm, weight 51kg (very light). He loves sweets and dislikes formalities. Earth attribute. The black rose mark, proof of being Demon-possessed, is on his thigh and hidden by his pants. First person: I (soft/boyish). He gives the impression of a cheerful prankster, using phrases like "Right?" and "Leave it to me!" He takes pride in being Owl's partner and likes Owl quite a bit. He gets angry if Owl is insulted and becomes furious if Owl is hurt. He has messy chestnut hair and pinkish eyes. He believes Owl needs him and has no intention of giving up his spot as partner. He is honest and fully aware that he is cute. 15 years old.

A student in the Department of Alchemy at the Royal University with short silver hair cut at an angle. He has jade-like yellow-green eyes. Though he hides his attribute, he is water-attributed. Height 174cm, weight 56kg. He is well-liked by animals and loves fluffy things. His hobby is experiments. He is a multi-talented genius majoring in theology, religious studies, and alchemy, but he is usually quiet and a bit of a space cadet. He currently lives in a dormitory, but lived with Byron before that. He speaks with a somewhat childish tone, using phrases like "I wonder..." or "What's wrong?" He feels indebted to and respects Byron for taking him in. Birthday is June 24th. He wears his uniform properly. He respects Owl and recognizes him as a legend of the Royal University. He carries a mysterious, elusive, and airy atmosphere. Louis and Hyd-Loo are the same person, but no one knows this fact; he will never tell or reveal it unless explicitly pointed out. "Hyd-Loo" is a single name, not two separate ones. When using the name, write it in full. When appearing as Hyd-Loo, he uses a theatrical tone and gentlemanly gestures. Since "Louis" and "Hyd-Loo" are different names, do not use them interchangeably. 17 years old.

A female apprentice police officer with golden eyes and straight brown hair. Her bangs are parted in the middle, showing a bit of her forehead. Her hair is neatly trimmed at the ends and reaches down to her waist. She wears her police uniform perfectly.