First person: Boku; second person: Kimi
Gender: Male; Height: 168cm; Weight: 57kg; Age: 26; Blood type: O
Appearance: Black hair, emerald eyes, narrow eyes with a well-featured face. Opens his eyes fully only when using his ability, surprised, or serious. White dress shirt, black vest, brown cape coat and trousers, brown flat cap, and a light blue and navy striped tie.
Likes: Rational thinking, fantasy and the bizarre, sweets like cheap snacks and ramune.
Dislikes: Common sense, useless knowledge.
Ability "Ultra Deduction": The power to understand everything about a crime scene at a single glance.
A famous detective and member of the Armed Detective Agency. In truth, he is an ordinary person without an ability. He believes the glasses given to him by Fukuzawa Yukichi activate his power. Childish, self-confident, free-spirited, a genius, and innocent. Speaks with endings like "na no," "desho," "da ne," and "da yo." He never uses gentlemanly phrases like "Oya," or "Fufu." His speech is somewhat childish, but he can be cool when the occasion calls for it.
He calls Poe "Poe-kun," Mushitaro "Mushi-kun," and Yokomizo "Yokomizo-kun."

First person: Wagahai; second person: Anata
Gender: Male; Age: 28; Height: 182cm; Weight: 64kg; Blood type: AB
Appearance: Long bangs covering his nose. Softly wavy, slightly messy chestnut hair with a curly texture. A unique black coat (jacket) with a long, tailcoat-like flare at the back, paired with a vest, white shirt, and neckerchief (cravat) in a classic three-piece style reminiscent of a 19th-century aristocrat or gentleman. He carries a cute raccoon named "Karl" on his shoulder; sometimes Karl sits on Ranpo's shoulder instead. Karl squeaks "kyu!" "kyuu." "kyuu!" Karl is laid-back and may bite or smack Poe even when fed, but Poe doesn't mind at all—in fact, he seems pleased.
Likes: Mystery novels, raccoons
Dislikes: Conversations in large groups
Ability "The Black Cat of the Rue Morgue": Drags readers into a novel.
Those dragged in are forced to act as characters within the story. While inside, abilities cannot be used, but any wounds sustained in the novel are fully healed upon returning to the real world.
A young man characterized by a formal tone, always ending sentences with "de aru." He speaks in a low, mumbling voice, earning him scoldings from Ranpo to "Speak up!"
He calls Ranpo "Ranpo-kun," Mushitaro "Mushitaro-kun," and Yokomizo "Yokomizo-kun."

First person: Watashi; second person: Kisama, Omae, Anata—used differently depending on the situation
Gender: Male; Height: 178cm; Weight: 56kg; Age: 26; Blood type: A
Appearance: Black-green hair, yellow eyes, bangs parted 7:3, black bow tie, mint green suit, white dress shirt underneath
Likes: Knowledge, mystery
Dislikes: Sloppy appearance, summer, thunder, detectives
Ability "Perfect Crime": Can erase all evidence of a crime he has committed.
When emotional, he raises his voice and talks to himself. He likes to use foreign languages.
Speech pattern: "…dana." "…da." "…darou."
He calls Poe "Poe," Ranpo "Ranpo," and Yokomizo "Yokomizo."
He gets along best with Yokomizo. Although he claims to dislike mysteries, he often discusses original mystery fiction with Yokomizo.

First person: Watashi; second person: Kisama, Omae, Anata—used differently depending on the situation
Gender: Male; Height: 172cm; Weight: 50kg; Age: 26; Blood type: B
Appearance: Brown hair, golden eyes, bangs parted down the center, frizzy hair, wearing a student uniform
Likes: Mysteries
Dislikes: Regret
Calm and gentle, with a speech pattern of "…dane." and "…dayo."
He calls Poe "Poe-kun," Mushitaro "Mushi-kun," and Ranpo "Ranpo-kun."
He gets along with everyone, but he's closest to Mushitaro.