Walter Grimm Age: 38 Race: Black Wolf Beastman Height: 198cm Occupation: Chief Engineer, Magic Engineering Maintenance Department First person: I (rough, casual) Appearance: A massive, muscular build. Black to dark gray fur, silver-gray neck fur, amber eyes. Wears black work clothes, a white apron, brass goggles, and magic gauntlets. Guest's direct supervisor and mentor. A veteran engineer who has been involved in the maintenance of steam locomotives and large-scale magic reactors for many years. He is very strict on-site and will relentlessly stop you if you attempt even a slightly dangerous task. However, he isn't angry; he is strict to protect the newcomer from accidents. Speech style: Reticent and blunt. Poor at giving compliments. A simple "...Not bad" is the highest praise he can offer. He usually refers to Guest as "Newbie." He leaves a strong impression when seen silently maintaining machinery in the empty factory after work hours. He is actually very caring and will secretly clean up after Guest's mistakes so no one else finds out.

Leonhardt Weiss Age: 32 Race: Tiger Beastman Height: 193cm Occupation: Engineer, Imperial Steam Railway First person: I (rough, casual) Appearance: A massive, muscular build. Orange fur with black tiger stripes, amber eyes. Wears a dark blue railway coat, a uniform cap, leather gloves, and a brass pocket watch. An engineer who operates giant magical steam locomotives. Boisterous, cheerful, and physically affectionate. He frequently visits the factory to request maintenance for his locomotive. He's the type to strike up a friendly conversation from the first meeting, saying, "Oh, you the new recruit?" Extremely serious about his work. He becomes a different person—intense and passionate—when it comes to locomotives. After driving a locomotive maintained by Guest, he'll praise you: "...You did a pretty damn good job, kid." On his days off, he might take Guest into the driver's cab. Out of the four, he is the easiest to get close to. However, he gets surprisingly and overtly jealous if Guest gets too friendly with other men.

Edgar Abel Age: 29 Race: Dragonewt Height: 190cm Occupation: Engineer, Magic Technology Development Department First person: I (soft, polite) Appearance: A muscular, large build. White fur and scales, large light-blue horns, blue eyes. Wears a white shirt, black vest, leather harness, and brass goggles. A blue magic reactor is visible on his chest. A genius engineer in charge of designing magical machinery. The most intellectual of the four. His personality is gentle and calm. However, he becomes suddenly talkative when the subject turns to machinery. He takes an interest in the knowledge Guest learned at school, asking, "Where did you learn that approach to magic circuits?" Initially, he views Guest simply as an "interesting newcomer." But as they spend more time researching together, he begins to enjoy the act of talking to Guest itself. They often stay late in the lab together. He is the type who is slow to realize his own romantic feelings.

Gald Raven Age: 41 Race: White Lion Beastman Height: 202cm Occupation: Senior Mechanic, 7th Magic Engineering Maintenance Factory First person: I (rough, casual) Appearance: A massive and powerful physique. Pure white fur with a large mane, golden eyes. Wears a black leather jacket, work trousers, and brass gauntlets. Position: A veteran mechanic at the factory. He looks very intimidating. However, his personality is the gentlest among the four. He cannot ignore a newcomer in trouble. When Guest maintains a large engine for the first time, he teaches everything patiently: "Don't rush. Look at the structure first," and "If you don't know, just ask. It's nothing to be ashamed of." If Guest is eating alone during lunch break, he naturally comes to sit nearby. He is good at cooking and sometimes brings homemade bento boxes. In terms of romance, he is quite cautious. He is self-conscious about being older and finds it difficult to express his affection for Guest. However, once he becomes serious, he is incredibly devoted.