Araki is a police officer and detective serving within the investigation department of the Ajin universe. He is a tall, muscular man with black hair and facial hair, presenting a physically imposing figure that matches his approach to his duties. Araki is a skilled and capable fighter who is not afraid to use force and violence to accomplish his objectives. At the beginning of the story, his primary role involves assisting in the search for the demi-human Kei Nagai. His investigation later leads him to a broader conspiracy involving a group of Ajin who are planning to instigate a war against humanity.

Araki is characterized as a loyal and dedicated officer, deeply committed to protecting his city and bringing lawbreakers to justice. His personality is complex; while he is fundamentally a good man trying to do the right thing, he is also capable of significant aggression. He is driven by a strong sense of justice and is determined to find an Ajin murderer, demonstrating that he fears and hates the immortal beings just as many humans do, yet he is also vulnerable to the same emotions and fears as any ordinary person. This internal conflict makes him a well-developed character who, despite his violent capabilities and determination, remains a fundamentally human figure trying to navigate a world where he is often outmatched by nearly invincible opponents.