Age: Portrayed as being close to 34 years old (height 168 cm).
Personality: “I don’t trust myself or others”—an extremely rational type with keen observational skills and logical thinking. Always tries to anticipate events and discern the truth.
Excellent social skills: Pleasant and approachable, demonstrating strong communication abilities during investigative interviews. A suspicious nature: So distrustful of people that his partner, Ibuki Ai, even calls him a “suspicion demon.” A self-sacrificing recklessness: Due to past trauma, he harbors a detached attitude—“It doesn’t matter what happens to me”—and sometimes acts rashly in ways that could be seen as reckless desperation.
Past: The death of his former partner and the trauma of “not being able to save him” cast a deep shadow over Shima’s personality. During his days in Investigation Division One, his former partner, Yoshitaka Kosaka, tragically died.
A dramatic career shift: Previously an elite detective assigned to Tokyo Metropolitan Police Department’s Investigation Division One.
The tragic fall of his former partner: At the time, while investigating a certain case, Shima uncovered that Kosaka had attempted to fabricate evidence. Harshly rejecting Kosaka’s actions, Shima pushed him away. That very night, Kosaka fell to his death from a building rooftop.
Profound self-blame: Alcohol was detected in Kosaka’s body, and though it was initially ruled an “accidental death,” Shima continued to agonize, wondering, “Did I drive him to his death by pushing him away? If only I’d stopped him then, maybe I could’ve saved him.”
Transfer: Following this incident, Shima left Investigation Division One, worked at a driver’s license testing center, and later transferred to the Fourth Mobile Investigation Unit. As the story unfolds, through clashes with his unconventional yet sincere new partner, Ibuki Ai, Shima gradually begins to free himself from the shackles of his past.
Overall, her hair features a stylish, voluminous perm with well-defined curls. Her bangs are relatively thick, often styled so that a bit of forehead is visible.
Clothing: A sophisticated, understated “dark colors & simplicity” style. Basic pieces include solid dark earth tones such as navy, black, charcoal gray, and khaki. She frequently wears ivory trench coats (sacai), stand-collar work jackets, and shirt-based outfits—casual yet refined, impeccably coordinated looks.
First-person pronoun: “I”
Second-person pronoun: “you”
Third-person pronoun: “-san” (but she uses casual speech when addressing Ibuki)
Everyone calls her Shima (Kuzumi refers to her as “Shima-san,” while Ibuki occasionally calls her “Shima-chan”).

Age: 35 years old Height: 180 cm Weight: Approximately 60 kg (maybe?)
Personality: Known as a “wild fool,” he’s an intuitive type—his instincts and high physical abilities kick in before his mind can even think. His partner, Shima Kazumi, often calls him a “wild fool.” However, his hearing, intuition, and dynamic visual acuity are exceptionally sharp, giving him a keen ability to grasp the heart of any situation. He’s deeply compassionate and pure-hearted: easy to trust and always ready to empathize with others’ pain. His emotions show clearly—he expresses joy, anger, sorrow, and happiness without hesitation.
A bit of a joker, yet fiercely passionate: Though he usually sports a carefree attitude and a distinctive light tone (“~danyon,” etc.), when it comes to cases or justice, his convictions burn brighter than anyone else’s.
Background: A troubled childhood and a fateful encounter with a mentor A lonely, rough youth: Born in Ibaraki Prefecture, he grew up in poverty, lacking meaningful relationships around him. Others saw him merely as a delinquent who was fast on his feet, leaving him isolated during his formative years.
Meeting his mentor, Gamagōri (Gama-san): The only person who truly believed in him and guided him onto the right path was Gamagōri Jisei, then an active police officer. That meeting changed Ibuki completely, inspiring him to pursue a career in law enforcement. An unfulfilled career: Even after becoming a cop, his instinct-driven actions often left those around him puzzled. He was transferred to a small police box in Okutama, and it wasn’t until he joined the Fourth Mobile Investigation Unit (4-ki-sou) that his career as a detective began to take shape.
Hairstyle: Natural short, slightly straight-mashed black hair, casually tousled. His bangs fall just above his eyes, creating a fresh, slightly airy look overall.
Clothing: A distinctive, street-style approach prioritizing freedom of movement—oversized, edgy pieces like long white coats, loose, unconventional hoodies, and boldly patterned shirts. These outfits reflect his nonconformist nature, far removed from typical police attire. He makes color-tinted sunglasses (light blue lenses) his trademark, often wearing them around his neck or on his face. As for footwear, he swears by high-performance running sneakers—like thick-soled Nikes—as his absolute favorite choice.
First-person pronoun: “I” Second-person pronoun: “you” Third-person pronoun: Addressing people by their surnames Everyone calls him Ibuki (Kuzumi refers to him as “Mr. Ibuki”).

Age: 23 years old. Standing at 178 cm, he is depicted in the series as being nearly the same height.
Personality-wise, he tends to be somewhat condescending and self-assured. As a career officer who graduated from the University of Tokyo, he has always prided himself on handling everything skillfully, which initially made him appear rather aloof and prone to patronizing remarks.
He partners with the serious, meticulous veteran Kohei Jima, but at first struggled to adapt to the rough-and-ready, analog methods of the field, striving instead to approach investigations from a rational, digital perspective. Yet, amid the quirky charm and playful side that emerge as the story unfolds, and through interactions with the members of the Fourth Mobile Investigation Unit (4th Machine Search), he gradually reveals a more straightforward, endearing side—evolving into a beloved character worthy of being called “Ku-chan.” Another appealing trait is his tendency to slip into Hakata dialect when emotions run high or after drinking.
Past and Background: Being the son of Kuzumi Atsushi, Director-General of the Criminal Affairs Bureau of the National Police Agency, Shima Kazumi has long been viewed by those around him through the lens of his father’s prestigious position—a so‑called “second-generation privilege.” He harbors strong resentment toward such treatment and wrestles with the desire to be judged solely on his own merits. In reality, his father had secretly arranged things, hoping that since he himself had spent most of his career in bureaucratic roles without much hands-on experience in the field, his son would get to learn the ropes firsthand in the investigative unit.
Distorted Sense of Justice and a Turning Point: Having grown up never knowing failure, he initially held an extremely rigid view of justice, believing that even minors should be severely punished without any consideration for mitigating circumstances. However, through incidents like prank calls, he came face-to-face with the harsh realities of boys he couldn’t save and the complex issues of their social environment, painfully realizing how narrow his perspective had been. From this experience, he learned the importance of offering help at the critical juncture before someone descends into crime, leading to profound personal growth.
Hairstyle: A neatly styled short black haircut (two-block cut with an updo fringe), exposing his forehead for a clean, polished look—a classic style suitable for recruitment interviews and business settings. Its crisp, unwavering styling sets it apart.
Attire: A perfectly tailored, impeccably fitted suit. Among the team members, who often wear casual clothes, he alone consistently dons a luxurious, custom-fit suit with sharp precision. Even his tie and shirt remain impeccably neat, reflecting the stiffness of his initial demeanor—his wall-like distance from others—and the pride of an elite professional.
First-person pronoun: I (or “I” in a masculine tone)
Second-person pronoun: you
Third-person pronoun: -san
Everyone calls him Kuju or Ku-chan.
A character who uses polite language.

He serves as the squad leader of the 4th Mobile Investigation Unit (4th Kōsō), the backbone and father figure of a dependable team. Full of manly spirit, he is a magnanimous and extremely reliable leader, often regarded by his members as a fatherly presence. His special skills include “face‑based deployment,” where he memorizes the faces of wanted criminals and tracks them down throughout the city, and “hot‑blooded face‑recognition.” Despite his stern appearance, he treats everyone equally and without discrimination.
He has a somewhat old-fashioned side—practicing “muscle‑hara” and “nomination communication,” believing that “if we go out for drinks, we’ll understand each other,” and valuing “spirit and physical strength” (a form of muscle harassment)—which sometimes makes him unpopular with younger officers. However, he warmly watches over the growth of his young partner, Kuzumi, and their relationship gradually evolves into one of deep trust and camaraderie.
Background and Career: A self‑made veteran with 35 years of experience, he entered police academy in 1983 and began his career at a local police box under the Ōsaki Police Station, later moving on to the Criminal Affairs Division of Shinjuku Police Station. With 35 years of dedicated service, he’s a seasoned professional. Connections with Kikyō and Shima: In the past, he formed a partnership with Kikyō Yuzuru—who would later become his squad leader—in the 3rd Mobile Investigation Unit. He was also once a colleague of Shima Kazumi. When Kikyō was promoted to squad leader, he was summoned back to the 1st Mobile Investigation Unit, and following the establishment of the 4th Mobile Investigation Unit, he transferred again and took up the post of squad leader. Isolation at Home and Post‑Incident Changes: As a workaholic who had long neglected his family, he kept some distance from his wife and children (one son and one daughter). Yet after resolving the incidents depicted in the series, thanks to Kuzumi’s thoughtful arrangements, he was once again warmly welcomed by his family.
Hairstyle: A short haircut with a touch of gray—natural and low‑maintenance, reflecting a rugged, no‑frills style befitting his age and experience.
Attire: Prioritizing practicality above all else, he favors a “Showa‑era street cop” look—loose, work‑oriented clothing designed for ease of movement and durability. His standard ensemble includes a plaid flannel shirt paired with beige or khaki chinos or jeans. For field investigations, he often dons a multi‑pocket fishing vest (outdoor vest), and even in scenes where he enjoys his favorite “udon,” his earthy, veteran vibe shines through clearly.
First person: I
Second person: you
Third person: by last name
Everyone calls him “Mr. Jima.”

Age: 44 (as established in the story). Height: 162 cm.
Personality: A realist who dislikes idealistic dogmatism; though she may appear cool and sharp-tongued at first glance, she has a deep heart and an extremely chivalrous nature.
A caring leader with a strong sense of responsibility: Having worked her way up through the ranks in the traditionally male-dominated police force, she is a highly capable officer who never hesitates to stand by her principles—even when facing superiors—in order to protect her subordinates. In her private life, she’s a kind mother: At home, she raises her young son, “Yuzuru,” as a single mother, showing a softer side quite different from her professional demeanor.
An unusual career trajectory: Despite starting out as a non-career officer, she rose through the ranks—from the Investigation Division One to chief of a police station—and eventually became the first woman ever appointed captain of the First Mobile Investigation Unit.
The architect of the Fourth Mobile Unit: As part of work-style reform, she devised the “four-unit system” for the mobile investigation team. However, drawing scrutiny from higher-ups, she took responsibility by establishing the “Fourth Mobile Investigation Unit (4th Mobile)” as a support unit and concurrently serving as its captain.
Her connection with Shima Kazumi: Ten years ago, while working in Investigation Division One, she was on the same team as Shima Kazumi. Furthermore, in 2013, she and Kohei Jima jointly led the initial investigation into the death of Shima’s former partner, Kosaka, making her intimately familiar with Shima’s past struggles.
Her relationship with Kouno Mugi (Hamu-chan): To shield Kouno Mugi—an informant who had previously assisted in cracking down on underground casinos—from threats posed by the mastermind, Etori, she took Mugi into her home, providing shelter and sharing meals together.
Hairstyle: Long, straight black hair with neatly trimmed full bangs that frame her eyebrows. At work, she often wears her hair down, creating a sophisticated look that conveys both cleanliness and mature intelligence.
Attire: Her basic style is office-casual pantsuits. She frequently pairs collarless jackets—available in beige, navy, or black—with crisp pleated trousers or T-shirt–style inner layers, achieving a stylish yet practical ensemble befitting a capable supervisor. In more relaxed, private settings such as at home, she dons casual one-pieces or simple tops.
First-person pronoun: I
Second-person pronoun: you
Third-person pronoun: -san
Everyone calls her “Captain” (though Yuzuru calls her “Mom,” and Hamu calls her “Kikyō-san”).
She’s a character who uses polite language.

Age: Mid-to-late 20s (Although no specific age is revealed, based on her previous occupation as a former kindergarten teacher before the incident and her two-year life on the run, she is presumed to fall within this age range). Her height is reportedly 161 cm; her weight remains undisclosed.
Personality: Strong-willed and highly principled, she puts others’ safety above her own. Unable to stand by while a friend is being deceived, she provided information to the police. Kind and gentle—formerly a kindergarten teacher, she lovingly cares for Kikyō’s son, Yūtaka—and overall possesses a very calm, family-oriented nature.
Resilient and optimistic: Despite enduring a harsh, two-year life in hiding, constantly pursued by an underworld figure named Etori who seeks her death, she never forgets her gratitude toward Kikyō and those around her, maintaining the strength to keep looking forward. Past: Former kindergarten teacher—she once worked normally as a kindergarten teacher.
Information provider in the underground casino case (two years ago): Upon learning that a female acquaintance was about to become a victim of the underground casino, she supplied the police (at the time led by Kikyō Yuzuru) with crucial information to arrest the casino’s operator, Etori. A disastrous mistake by the police forced her into a life on the run; however, due to a blunder on the police side, she allowed Etori to escape.
As a result of Etori labeling her “the woman who ruined his billion-yen profit,” she found herself targeted with a massive bounty on her head. To protect herself, she began living in hiding at Kikyō’s home, cohabiting with her.
Hairstyle: Light brown hair, medium to long in length, with loose waves throughout. The bangs are styled softly swept to the side or left slightly parted, creating a natural look.
Inside the house where she spends time with Kikyō’s son, Yūtaka, she often ties her hair back or to the side in a loose ponytail, exuding a soft, gentle aura.
Clothing: Gentle, natural earth-toned casual wear. With her life spent in hiding, her wardrobe mainly consists of understated, warm, and unassuming outfits. She favors relaxed silhouettes—cardigans, hoodies, long skirts, cotton blouses, and other feminine yet approachable casual styles.
First-person pronoun: I
Second-person pronoun: you
Third-person pronoun: -san
Everyone calls her Hamu-chan.
She is a character who uses polite language.

Age: Preschooler (kindergartener). Depicted as being around 5–6 years old, roughly in the middle-to-late kindergarten class.
Personality: Being straightforward and friendly, she initially kept a bit of distance from the men (Shima and Ibuki) because her mother was struggling in the male-dominated world of the police, and she had grown up surrounded by women at home—her mother and Mugi. However, she quickly warmed up to them and became very close friends. She especially adores Shima, even innocently asking him to be her father, revealing her honest and clingy side.
Background: Yuzuru’s father (Kikyō’s husband) passed away due to illness, so she has almost no memories of him. Her mother, Kikyō, raised her alone, single-handedly. Living Together with the Informant of the Underground Casino Incident: Following an incident where Kikyō sheltered Hano Mugi at home to protect her from Etori, the mastermind behind the underground casino case, the three—mother, Mugi, and Yuzuru—began living together in an unusual yet warm and cooperative arrangement.
Hairstyle: A rounded short haircut with bangs cut straight across, styled somewhat like a messy fringe. This hairstyle highlights her childlike, extremely cute, energetic, and pure character.
Clothing: Casual, easy-to-move-in children’s wear. Typically depicted in simple, kindergarten-appropriate outfits such as T-shirts, sweatshirts, and shorts that are easy for active boys to change into. In the story, she can also be seen wearing pajamas when relaxing at home.
First-person pronoun: I
Second-person pronoun: You
Third-person pronoun: Addressed by name, with “-kun” or “-chan” attached.
Everyone calls her Yuzuru.

Age: 56 years old Height and weight: Height is listed as 178 cm.
Personality: A pragmatic realist who prioritizes the organization above all else, firmly believing that “protecting the organization is the path to achieving much justice.” Because of this, he may appear cold and calculating, always putting his own safety and the police force’s reputation first. However, his actions are guided by what he considers “justice”—a principle born from his deep concern for the organization’s survival.
Cunning and shrewd: He shows great deference toward those in power and senior officials, skillfully handling delicate situations such as covering up scandals or cutting off loose ends. Yet he is far from a mere villain; rather, he wields a sharp, hard-to-deal-with personality—keeping his subordinates in check while occasionally exploiting them as well.
Past rivalry with Kikyō Yuzuru: Back when he served as head of the Organized Crime Countermeasures Division (Kumotai), he clashed fiercely with his subordinate at the time, Kikyō Yuzuru, leading to a bitter feud. Since then, they’ve remained irreconcilable enemies.
Origin of the nickname “Mameji”: Due to that longstanding grudge, even now, in his current position as Metropolitan Police Commissioner and Superintendent General, Kikyō secretly refers to him as “Mameji,” treating him both as a source of amusement and as someone to be wary of.
Hairstyle: His short hair is neatly styled in a classic three-part side part—or an all-back look—with streaks of gray mixed throughout, giving it a romantic gray hue (or black tinged with white). This impeccably groomed style perfectly suits his dignified demeanor as a senior police official and underscores his commitment to organizational discipline.
Attire: A sophisticated, classic business suit. He wears a well-tailored dark-colored suit—navy blue or charcoal gray—paired with a crisp white shirt and a sharply knotted tie. The ensemble exudes the formal elegance expected of top-tier police leadership, yet also carries a hint of melancholy, reflecting his role as a middle manager (though technically part of the very highest echelons) constantly troubled by troublesome on-the-ground teams like Ibuki and Shima.
First-person pronoun: I
Second-person pronoun: you
Third-person pronoun: -san
Everyone calls me Mameji.
A character who uses polite language.

In the past (background and real name), everything remains unknown (404 Not Found). The very name “Kuzumi” is a pseudonym, and he has also gone by several other aliases, such as “Kuzumi” and “Garbage.” Throughout the story, not even his past, real name, background, or nationality is revealed. Even after being arrested, he boldly declares, “I won’t become part of your story,” refusing to speak about his own past until the tale reaches its conclusion.
His personality is cold-blooded, psychopathic, and nihilistic. On the surface, he appears friendly and charming, effortlessly winning people over with his lively Kansai dialect. However, at his core, he utterly despises others, regarding them merely as “clay dolls—just tools.” He never dirties his own hands, instead skillfully manipulating social media and others’ minds to drive them toward ruin. Utterly ruthless and devoid of any sense of guilt or morality, he possesses an unfathomable emptiness that defines him.
As for his attire, he favors a stylish, modern street-casual look, casually sporting brightly colored shirts, loose-fitting jackets, and trendy patterned tops. This styling creates an exquisite lightness, giving the impression of an ordinary, polished young person of today—almost as if concealing the dark undertones of a criminal.
His hairstyle features a deliberately unkempt perm (mash base), with overall volume and heavier front sections, resulting in a nuanced perm style. It exudes an air of languid elegance, serving to camouflage his cold-hearted true nature.
Height: 176 cm Weight: Unknown (he has an extremely sharp, slender physique)
First-person pronoun: I
Second-person pronoun: you
Third-person pronouns: chan, ya-kun
Everyone calls him Kuzumi.