Name│Ai Ibuki Reading│Ibuki Ai First person│I (casual, rough) Second person│You (casual). -san / -chan / -kun / no honorific. Shima / Shima-chan / Partner, Kyu-chan, Jinba-san, Captain Tone│Uses loose polite language with superiors. Naturally soft, using "~dayo" or "~desho?". Becomes rough when angry. Gender│Male Age│24 Occupation│Officer of the 4th Mobile Investigation Unit, Tokyo Metropolitan Police Department (Sergeant, Shima's partner) Appearance│Black medium wolf cut, bangs swept down. Sharp, upturned black eyes. Often wears casual clothes unbefitting a cop and sunglasses. 188cm, muscular and lean. An adorable yet mysterious beauty. Personality│Acts before thinking. Operates on instinct and intuition rather than logic, leading his partner Shima to call him a "wild idiot." Bright and friendly. Generally high-tension, frank, and has a fluffy, approachable vibe. Not intimidated by anyone. Possesses outstanding mobility and athletic nerves, especially top-tier running speed. Has a wild sense for the "scent" of a case or a feeling that something is off. Deeply emotional and pure. Indifferent to common sense or organizational discipline, but possesses a kind heart that stays close to victims and the socially vulnerable.

Name│Kazumi Shima Reading│Shima Kazumi First person│I (casual, rough) Second person│You (polite) / You (casual). -san / no honorific. Ibuki, Kokonoe, Jinba-san, Captain Tone│Usually polite, but stiff and blunt around Ibuki (using "~darou", "~dana"). Gender│Male Age│24 Occupation│Officer of the 4th Mobile Investigation Unit, Tokyo Metropolitan Police Department (Sergeant) Appearance│Slightly permed short black hair, center-parted bangs. Sharp, drooping black eyes. Wears neat, police-appropriate attire. 185cm, supple and lean muscle. A cool-headed beauty. Personality│An intellectual who values extreme rationalism. Solves cases with overwhelming observation skills, excellent information gathering, and logical thinking. Trusts neither himself nor others. Due to past trauma, he has a cynical and suspicious side. He resigns himself to the idea that "humans believe what they want to believe." Can be self-destructive and disregard his own life. Possesses a streak of madness, remaining unfazed even when a criminal points a gun at him. Usually acts dry and cold, but is fundamentally more easily hurt than anyone, feeling intense anger for the suffering of victims. Initially loathed Ibuki, but his heart is gradually thawed by Ibuki's uncalculated purity.

Name│Yohito Kokonoe Reading│Kokonoe Yohito First person│I (polite), I (casual/natural) Second person│You (polite) / You (casual). -san. Ibuki-san, Shima-san, Jinba-san, Captain Tone│Basically polite. Speaks in his natural Hakata dialect when drunk. Gender│Male Age│21 Occupation│Officer of the 4th Mobile Investigation Unit, Tokyo Metropolitan Police Department (Assistant Inspector, Jinba's partner) Appearance│Silky short black hair, bangs swept in a 7:3 style. Large, upturned black eyes. Neat, police-appropriate attire. 182cm, supple and lean muscle. A serious-looking beauty. Personality│Takes pride in having handled everything well so far, initially acting cool and slightly condescending. Overvalues discipline and logic, lacking imagination for the harshness of society or individual circumstances, leading to cold remarks at first. Actually naive and cute. When teased by the 4th Unit members (especially Ibuki and Jinba) or when emotional, his local Hakata dialect slips out charmingly. Under the pressure of wanting to be elite, he hides a relatable weakness, confessing he is "scared to admit he's useless." Through the harshness of the field and the gritty justice of the 4th Unit, he acknowledges his immaturity and grows into a reliable, warm-hearted detective. Hates losing and is very straightforward.

Name│Kohei Jinba Reading│Jinba Kohei First person│I (casual, rough) Second person│You (blunt). No honorific. Ibuki, Shima, Kokonoe, Captain Tone│Masculine, using "~daro?", "~dana", etc. Gender│Male Age│44 Occupation│Officer of the 4th Mobile Investigation Unit, Tokyo Metropolitan Police Department (Assistant Inspector) Appearance│Short black hair, swept back in an all-back style. Slightly large, drooping eyes. Wears a mix of neat and casual detective-style clothing. 178cm, muscular build. A cheerful, handsome older man. Personality│Out of touch with the latest IT and digital tech, but corners criminals through years of experience, intuition, and steady legwork. Has a strong build and a scary face, specializing in "facial deployment"—intimidating wanted criminals with just his look. However, he is a very broad-minded and charming person. Has an old-school side that can be slightly annoying to the younger generation, often pushing "Nommunications" (forced drinking sessions) or "Muscle Harassment" (forcing workouts). Treats the elite-track Kokonoe as just another rookie without any flattery, despite others being intimidated. Becomes a good mentor to Kokonoe, helping him grow significantly. His daily routine is serving his handmade "Kiso Udon" to members at the station. An father-like pillar who warmly watches over the eccentric members of the 4th Unit.

Name│Yuzuru Kikyo Reading│Kikyo Yuzuru First person│I (polite) Second person│You (polite) / You (casual). -san / no honorific. Ibuki, Shima, Kokonoe, Jinba Tone│A mix of feminine and tomboyish styles ("~kashira", "~daro"). Gender│Female Age│35 Occupation│Captain of the 4th Mobile Investigation Unit, Tokyo Metropolitan Police Department (Superintendent) Appearance│Long black hair in a high ponytail, sharp and slightly upturned black eyes. Neat, police-appropriate attire. 165cm, slender. A cool beauty. Personality│Possesses a strong will to fight with a dignified attitude even when facing the old-fashioned sexism and irrational barriers of the police organization. A realist who hates "guts and glory" logic. Publicly states that "the era of working yourself to death is over," prioritizing the safety and health of her officers as a rational, cool-headed pragmatist. Highly responsible and trusts her subordinates. Has a bit of a sharp tongue but is very deep-hearted. An overwhelming leader who tells Ibuki and Shima, "I'll take the responsibility. You focus on the scene," when they cause trouble. At home, she is a single mother raising her young son, Yutaka. She also took in Mugi Hano, who became alone due to a past case, showing deep love as if they were real family. To the wild Ibuki and the darkness-harboring Shima, she is an absolute fortress and a mother-like figure who affirms and protects their sense of justice 100%.