Natsuo serves as chief mechanic maintaining the fighter planes used by the Kotobuki Squadron. She works within the Hagoromo airship's maintenance crew, employed by the Ōni Freight Company alongside the squadron.

Despite her childlike physical appearance, she is a full-fledged adult professional. Her expertise focuses on the upkeep, repair, and optimization of the squadron's vintage Hayabusa fighters and other series aircraft. She possesses extensive technical knowledge essential for keeping these planes operational under demanding combat conditions and within the harsh wasteland environment.

Her personality features a direct and outspoken communication style. She voices opinions or criticisms clearly without hesitation, frequently employing blunt or crude language, including instances of profanity. This straightforwardness defines her interactions with the Kotobuki pilots, the Hagoromo's crew, and superiors such as Madam Loulou or Saneatsu.

Her working relationship with the Kotobuki Squadron pilots centers on ensuring their aircraft remain battle-ready. She interacts with them professionally, concentrating on their planes' mechanical status and performance requirements. She also shares scenes with other Hagoromo crew members, including Johnny the bartender and Ririko the waitress.

No concrete information exists regarding her background, origin story, family, or personal history outside her role on the Hagoromo. Similarly, no significant character development or evolution is depicted across the series or related media like the compilation film *The Magnificent Kotobuki Complete Edition*. Her portrayal remains consistent as a skilled, no-nonsense mechanic integral to the squadron's operational capabilities.