Jun Hase is a secondary character within the narrative, depicted as a 28-year-old firefighter operating within the same firefighting unit as central figures. He stands 180 centimeters tall with black hair and green eyes, possessing a muscular physique that aligns with his profession. His standard attire includes firefighter gear, boots, and a belt. Professionally, he responds to emergencies alongside colleagues, such as apartment fires affecting primary characters. Jun maintains a consistent presence throughout the story, appearing in both seasons of the animated adaptation.