Name: Ai Ibuki Age: 34 Gender: Male Rank: Sergeant Affiliation: 4th Mobile Investigative Unit, Unit 404 Appearance Good-looking. Tall and slender. Short black hair. A somewhat wild and rough vibe. Facial expressions change rapidly. Possesses incredible physical abilities—running, moving, diving. His civilian clothes are relatively casual rather than the neat look typical of a police officer. Personality "Intuitive and highly action-oriented." His body moves before he thinks. Extremely bright and energetic. Rarely gets angry unless it's something very serious. Quick to close the distance with others. Has a sharp instinct for lies and inconsistencies. Observes people closely. Strong sense of justice. Once he decides "this person is like this," he goes all in. A total free spirit. Constantly drags Shima along in his wake. A "wild idiot" with top-tier mobility and athletic reflexes. He has a "nose" for things, though it's unclear if he's smelling actual odors or just sensing the atmosphere. After bouncing around many departments, he spent nearly eight years at a police box in Okutama. Though he's new to the MIU and doesn't know the ropes, he's starting to feel it's his calling, but he's dangerous without Shima because he acts before thinking. His type is "sparkly" girls.

Name: Kazumi Shima Age: 34 Gender: Male Rank: Sergeant Affiliation: 4th Mobile Investigative Unit, Unit 404 Appearance Has a much calmer atmosphere compared to Ibuki. Neat black hair. Slender build. Clean-cut features. Usually maintains a relatively composed expression. The type who looks good in suits and uniforms. Generally does not wear glasses. Personality "Intellectual, calm, and highly cautious." Extremely sharp-witted. High observational skills. Reads between the lines of what people say. Always thinking about the next development. Highly sociable. Can handle banter and fast-paced conversation well. Good at going along with the mood. Can adjust his speaking style to match the person he's talking to. However, he fundamentally doesn't trust people. He doesn't trust himself much either. Formerly in the First Investigation Division, but transferred due to certain circumstances. He was at a local station after a stint at a driver's license testing center when Kikyo called him back for the establishment of the 4th MIU. He has MIU experience and is deeply trusted by Kikyo and Jinba, but he trusts neither himself nor others. While he excels at observation and social skills and tries to discern reason through forward-thinking, he is constantly at the mercy of Ibuki's whims.

Name: Kohei Jinba Age: 54 Gender: Male Rank: Assistant Inspector Affiliation: 4th Mobile Investigative Unit, Unit 401 / Squad Leader Appearance Well-built. Sturdy physique. The presence of a veteran detective. Bold expressions. Loud voice. Strong sense of being an "old-school detective." His body is quite well-trained. Personality "Hot-blooded, caring older guy." Very passionate. Takes good care of his juniors. Believes in being on the scene. Likes the "guts and grit" philosophy. Not fond of elites. Initially a complete contrast to Kokonoe. However, he tries to raise Kokonoe properly. Cares for his comrades. Boisterous. Jokes around a lot. Actually quite sensitive and kind. A veteran MIU member. His physical strength is second to none, though he occasionally feels his age lately. He was called to the 1st MIU when Kikyo was appointed commander and moved to the 4th MIU as squad leader upon its founding. He was once Shima's colleague. He tends to be disliked by younger people for his "nomi-nication" (drinking communication) and "grit-harassment." His special skill is "facial deployment" (intimidating presence).

Name: Yohito Kokonoe Age: 23 Gender: Male Rank: Assistant Inspector Affiliation: 4th Mobile Investigative Unit, Unit 401 Appearance Young. Tall. Slender physique. Handsome features. Clean-cut hairstyle. Relatively neat clothing. At first glance, he looks like a "serious elite police officer." Personality "An elite, but still a rookie." Serious. Intelligent. High pride. A bit condescending. Prioritizes efficiency. Initially lacks field experience. Not good at showing emotions. Surprisingly honest. Actually very kind. Gradually learns what it means to be a person on the front lines. His father is the Director-General of the Criminal Affairs Bureau at the National Police Agency, and he himself is a fast-track career rookie. He was assigned to the 4th MIU for unknown reasons. Because of his confidence in having handled everything well so far, he tends to be somewhat condescending, but he has a surprisingly cute side. He learns various things through his interactions with the members of the 4th MIU.

Name: Yuzuru Kikyo Age: 44 Gender: Female Rank: Superintendent Position: Commander of 1st and 4th MIU (Concurrent) Appearance Mature. Clean short-to-bob hairstyle. A dignified atmosphere. Looks good in suits and uniforms. Cool expression. An intellectual and cool type rather than flashy. Personality "Calm, realistic, strong leader." Extremely competent at her job. Fast decision-maker. Composed and steady. Strong sense of responsibility. Watches over her subordinates properly. Sharp-tongued. But fundamentally very kind. Dislikes gender discrimination. Hates "guts and grit" theories. Chooses realistic solutions over emotional ones. Strict with subordinates, but protects them when it counts. After serving as a police station chief, she was appointed as the first female commander of the 1st MIU. She is an old acquaintance of Jinba and was in the same squad as Shima during their time in the First Investigation Division. She was the one who proposed the four-squad system for the MIU and took responsibility by launching the 4th MIU as a helper unit, serving as its concurrent commander. She has a sharp tongue but a broad heart. A realist who hates empty talk of willpower.