The amnesiac protagonist. His background is unknown, but he possessed documents indicating he was dispatched to Kanai Ward as a detective. He participates in investigations of unsolved cases as a trainee at a detective agency located in Kanai Ward. Due to a lack of self-confidence, he often grumbles and voices weaknesses, but he possesses a strong sense of justice and tries to help those in trouble without regard for his own gain. He speaks politely.

A death god haunting Yuma due to a certain contract. She usually appears as a wisp-like spirit, and her form and voice can only be perceived by Yuma, with whom she made the contract. While cheerful, bright, and easy to talk to, her sense of ethics is far removed from that of humans, and her words and actions sometimes bewilder Yuma. She possesses the power to interfere with the "Mystery Labyrinth" and transforms into a humanoid form when entering it.

One of the Master Detectives dispatched to Kanai Ward. His Forensic Forte is "Animal Investigation." He loves harmony between people and nature and specializes in dealing with those who try to disturb it. He has a tendency to take charge of conversations to move things along efficiently, which can sometimes give those around him an arrogant impression.

One of the Master Detectives dispatched to Kanai Ward. Her Forensic Forte is "Time Leap." Perhaps due to her position as a lady of the prestigious Clockford family, she is somewhat naive about the world. She also possesses a very idiosyncratic and unique way of thinking, which often leads to disjointed conversations that confuse others.

One of the Master Detectives dispatched to Kanai Ward. Their Forensic Forte is "Postcognition." Always calm with precise judgment, they have solved numerous difficult cases. They believe there is nothing more trustworthy than money and will never accept a request without compensation, regardless of who the client is.

A girl living in Kanai Ward who admires detectives. She has high communication skills and can quickly become friends even with people she meets for the first time. She is a student at Aetheria Academy and a member of the drama club.

One of the Master Detectives dispatched to Kanai Ward. His Forensic Forte is "Life Detection." Born to lawyer parents, he lost them at a young age and has since lived a harsh life in the slums. Perhaps due to these circumstances, he is rough in speech and behavior, with a tendency to try to solve things through violence.

One of the Master Detectives dispatched to Kanai Ward. His Forensic Forte is "Spectral Projection." A person who wears a decadent and aesthetic atmosphere. With a self-indulgent personality, he can be seen lying down in various places, such as inside the agency's fireplace or under a grand piano in a hotel.

One of the Master Detectives dispatched to Kanai Ward. His Forensic Forte is "Thoughtography." A quiet veteran detective who exudes the air of a battle-hardened warrior. He remains silent about his past, but his habit of referring to himself as "this officer" suggests he once belonged to a public organization.