Manabu Aki commands the Aki Team, the aerial unit of the Rugger Team’s exploration and defense force, piloting Rugger #1 as the head of the combined super-robot Dairugger. Respected as "Chief" by his crew, he oversees missions where their vehicles merge into the Kurugger, bolstering Dairugger’s airborne prowess. Tasked by the Galaxy Garrison’s Rugger Guard, he charts uncharted galactic territories and evaluates worlds for colonization, a role disrupted by clashes with the hostile Galveston Empire. Despite prioritizing diplomacy, their aggression forces him into strategic defense.

A mission to Planet K profoundly shifts his perspective after engaging with its native inhabitants, embedding environmental stewardship into his tactics to curb battlefield ecological harm. His leadership melds impulsiveness with empathy—bold, occasionally rash decisions tempered by unwavering loyalty to his team. A memorable culinary clash underscores his meticulousness when a chef ignores his sugar-free curry request, revealing his stubborn streak.

Divergent portrayals in alternate media cast him as a child in the manga, stripping the anime’s exploration themes for a distinct narrative path. Beyond his tactical acumen, he enjoys alcohol, though its role remains unexplored. Central to his identity is uniting the Keets and Walter Teams, synchronizing Dairugger’s operations to repel threats, cementing his role as the linchpin of collaborative defense.