Hirokazu Arai

Arai is serious about devil hunting and initially approaches Denji with suspicion. He believes that Denji's unusual circumstances make him dangerous and is much less willing than Himeno to accept him immediately as a colleague. He can also be competitive and insecure, particularly when comparing his own abilities with those of more naturally gifted hunters.

Underneath that insecurity is a strong sense of responsibility. Arai is attentive when his companions are sick or injured and is willing to perform unpleasant tasks to help them. Himeno judges that he is not especially talented but values his motivation, an assessment that accurately describes the persistence with which he approaches the job.

His conduct during the Eternity Devil incident also exposes the limits of his courage. Fear and exhaustion push him toward accepting the group's apparent only means of escape, yet he remains capable of putting himself in danger for another person when circumstances demand it.

Arai is a trained Public Safety Devil Hunter with experience in close-quarters combat and the physical conditioning required for field assignments. He fights the Eternity Devil's manifested flesh with a sword and can continue operating under dangerous conditions despite his relative inexperience.

He has a contract with the Fox Devil. The precise terms and extent of his contract are not established, and the manga does not show him using the Fox Devil as extensively as Aki Hayakawa.

Arai's greatest practical strengths are persistence and willingness to cooperate. He is not portrayed as an exceptional fighter among Public Safety's personnel, and Himeno explicitly identifies drive rather than talent as his defining quality as a Devil Hunter.

Arai enters Public Safety as one of the newer Devil Hunters working under Makima. He participates in the operation at the hotel where the Eternity Devil traps members of Special Division 4 on the eighth floor. As their supplies and patience deteriorate, Arai joins Kobeni in arguing that Denji should be sacrificed to satisfy the devil's demand.

After the group escapes, Arai attends the Division 4 welcome party and becomes part of the everyday professional circle surrounding Denji, Aki, Himeno, and Kobeni.

During the coordinated assault on Public Safety, Arai shields Kobeni from gunfire and is killed protecting her. His action reinforces the loyalty that had been present beneath his anxious and sometimes confrontational behavior.

Kobeni Higashiyama is Arai's partner in Public Safety. Although both become overwhelmed during the Eternity Devil incident, Arai cares about her safety and ultimately protects her with his own body during the attack on Public Safety.

Himeno trained Arai for approximately six months. She considers him lacking in natural ability but praises the determination with which he compensates for it.

Denji initially receives little trust from Arai, who views his connection to devils with suspicion. Their relationship becomes more cooperative through shared missions.

Aki Hayakawa is one of the senior hunters with whom Arai works during the Eternity Devil operation.

Makima oversees the special division to which Arai is assigned.