Kōzaburō Arase

Kōzaburō Arase (荒瀬 耿三郎 Arase Kōzaburō) is a former yakuza who works as a detective for the third Materials Compiling Group of the Shinjuku Police's community safety division.

Appearance
Arase has short black hair, brown skin, and a lean, athletic build. He is usually seen wearing a black shirt tucked into nice trousers, and occasionally a grey jacket. A large yakuza tattoo covers the majority of his back, featuring a tiger superimposed over flowers and flowing water.

Personality
Arase has been compared to a 'wild animal' and a 'carnivore' by those who have seen him fight and as such for what he is: a brave, skilled, and dangerous man for whom violence comes naturally. He acts the bad cop to Tsubaki Iwanome's good cop by choice, though not obviously so at first glance: he usually stays quiet while Iwanome talks with interviewees rather than act a threatening aggressor; and rather than contrast Iwanome's bright smiles with an intimidating glower, he often wears a slight, polite smile of his own.

It is because Arase is Iwanome's stolid shadow that he can be so effective and frightening as a 'bad cop': when he has to physically intervene on Iwanome's behalf, it is with sudden, firm strength that is striking all on its own; when he warns a teenager to stay away from 'lowlifes' lest the teen become one too, he does so with an intensity that turns his smile into more of a warning than a kindness; he can exude danger with a glance. Arase is at his most alive when fighting or giving chase to someone else, wild and bright-eyed in a way that contrasts his cool demeanor most of all.

Despite or because Arase was once yakuza, he has a low opinion of lowlifes and appears to dislike the idea of 'working with' troublemakers; he furthermore calls himself a 'scumbag' in reference to his reliance on violence and killing.

Background
Originally with the yakuza, Arase for reasons unknown leaves the underworld and joins the police—using his underworld ties to conduct multiple illegal cover operations that have never been made public. He is later punished for these operations and "chewed out" for them by Danjo Tozawa. Either when or after he joins the police, he joins Materials Compiling Group No.3 as a detective.

Before the start of the series, Arase attacks the gang Sons of the Styx and beats eight of its members within an inch of their lives. The incident leaves a deep impression on the gang's informant Takumi Kuruya and Higuro, the gang's leader, whom Arase will remember in turn as a lowlife and as dangerous respectively, and leads to the gang's dissolution.

Present
To be added.