Rob Onwa, the 25-year-old chief engineer of the lunar warship *Queen Fuji*, maintains a well-built physique honed by engine-room labor, yielding above-average strength that contrasts his gentle, softhearted nature. He takes profound pride in both the warship and his officer rank, expressed through meticulous system maintenance. His technical curiosity ignites upon witnessing gynoid Iczer-3’s combat prowess, driving him to grasp rudimentary alien technology.

Throughout the series, a gradual romantic bond forms with Captain Candy Barts, adding personal depth to his role. Background reveals his parents operated a renowned Chinese restaurant, uncovered during an impromptu cooking contest with Atros in CD drama content, showcasing culinary skills beyond engineering. In a separate "gag drama" episode, he whimsically remodels the ship’s galley with "anime-like magnificence," causing Captain Candy mild embarrassment yet highlighting his technical zeal. Interactions with crewmates like Yajin Ro consistently reinforce these traits.