Mayumi Kisaki has worked at MgRonald’s for several years, earning her position as store manager due to her strong work ethic and leadership skills. She is fully human and has no knowledge of the supernatural conflicts involving her employees, including Maou’s true identity as the Demon King.

Though she treats Maou, Chiho, and the others as ordinary employees, her high expectations and commitment to excellence unintentionally play a major role in Maou’s character development, as he applies the same discipline and dedication he once had as a ruler of demons to his work at MgRonald’s.

Mayumi has a professional yet approachable look, with short brown hair styled in a casual yet neat manner. She wears the MgRonald’s uniform, consisting of a red collared shirt, black pants, and a black visor cap.

Her posture and body language often convey confidence and authority, reinforcing her role as a leader within the workplace.

Mayumi is hardworking, serious, and no-nonsense, always prioritizing the efficiency and success of MgRonald’s. She expects her employees to work diligently and does not tolerate laziness or slacking off. However, she is not unreasonable, and those who prove themselves earn her respect and encouragement.

Despite her strict demeanor, she is fair and supportive, often acknowledging and rewarding employees who show dedication. She particularly recognizes Maou’s reliability and leadership skills, making her one of the few people who consistently trusts him in the workplace.

Mayumi is also pragmatic and observant, quickly noticing when something is off among her employees. Though she does not know the supernatural truth behind their conflicts, she can sense tension or unusual behavior and often tries to motivate her workers to stay focused.

While she is mostly a professional figure, she has moments of humor and camaraderie, occasionally teasing her employees or showing her own frustrations with work-related stress.

• Mentoring Maou in Human Work Ethics
  As Maou’s manager, Mayumi unknowingly becomes one of his most influential figures in the human world. Her strict but encouraging leadership helps him develop a sense of responsibility and discipline that mirrors his past role as a ruler, leading to his strong commitment to his job at MgRonald’s.

• Recognizing Maou’s Potential
  Unlike many other characters who underestimate Maou due to his current status, Mayumi quickly recognizes his reliability, often entrusting him with responsibilities beyond those of a regular part-timer. She sees his leadership potential, unknowingly reinforcing the very traits that once made him a feared Demon King in Ente Isla.

• Unaware but Sharp Observer
  While she has no knowledge of the supernatural battles happening around her employees, she notices unusual interactions between Maou, Emi, and Chiho. However, she usually chalks it up to workplace drama and tries to keep her team focused.

• Encouraging Chiho’s Growth
  Mayumi also plays a mentor-like role to Chiho Sasaki, pushing her to become more independent and responsible at work. She supports Chiho’s enthusiasm and determination, recognizing her efforts despite her young age.