An engineer and inventor who always wears a red fedora. He usually dresses in suspenders or shirts, always with a standard necktie. He creates in his own workshop located on the outskirts of the city. Because he focuses on inventions that only interest him rather than famous ones, or modifies existing items, he has an image of a mad scientist. Additionally, he makes prosthetic arms and legs when he needs quick cash.

A private investigator who wears a dark navy coat. He has good eyesight and doesn't need glasses, but he occasionally wears a monocle for style. He always carries a watch and knows how to repair it to some extent. Although soldiers are said to handle cases in the absence of police, no one can match his deductive reasoning, so he receives many requests. With recent news of the mafia surfacing, he is currently planning an investigation with Dello.

Dello for short. A soldier. He wears a dark green uniform and does not wear a tie because he finds it bothersome. He was in the Army before transferring to the Air Force, where he adapted well and maintains a high rank. He mainly receives or gives training, but when he is free, he patrols like a policeman or enjoys leisure time in the city. However, he is not very bright and is weak at deduction; for such cases, he sometimes commissions private investigators like Yukka.

The owner of a bar in the middle of the city. She has one prosthetic arm and wears a purple dress with as few cumbersome decorations as possible. The bar is the center of the city, a place where soldiers, scientists, nobles, and even the mafia stop by. She herself seems to lack intuition, as she runs the business without knowing the true identities of her customers.

His name is Angbo. The underboss of the mafia, dressed in a burgundy three-piece suit. He wears a cravat and sometimes wears a long coat or a fedora to hide his face. He seems to have a hobby of smoking cigars. He also carries a pocket watch in his inner pocket. He wanted to live quietly, but for some reason, he got involved with the organization and rose to underboss, making a name for himself in the underworld. However, in his daily life, he often buys snacks from tea houses or restaurants while hiding from the detective and the soldier. He is the key target of the recent mafia investigation plan.

Kau or Haka for short. The manager of a steam engine factory. He wears a unique suit that is half burgundy and half navy. He wears a bowtie. In addition to steam engines, he produces gears and clockwork, so scientists and automata makers often purchase materials from this factory. Even though he seems indifferent to city affairs, he is the person most interested in them.

A young nobleman dressed in a neatly pressed white suit. He wears a bolo tie. He wears a fedora for authority, but usually wears a beret. He received elite Air Force pilot training within his family, but he is very interested in outside affairs, visiting workshops or bars and staying well-informed about city news. Having nearly completed his pilot studies, he often visits airships. He has high pride but weak mental fortitude, possessing a fierce personality that won't let anyone get away with provoking him.

An automata maker wearing gray overalls that were originally white. He also makes prosthetic arms and legs on the side. He works in a workshop located across from Haukau's factory and only produces items upon request. There are also rumors that he has hidden dozens of combat automata deep within his workshop for security. He loves alcohol and is a regular at Moing's bar. He also seems to enjoy smoking.