Vice Admiral Susumu Fuji holds the senior leadership position of Chief of Staff for the United Planets Space Force. He frequently acts as a counterbalance to Fleet Admiral Mifune's volatile temperament, attempting to calm his superior during outbursts though rarely succeeding. Outwardly cautious and reasonable, this demeanor masks a fundamentally ruthless, crafty, and cunning personality willing to employ underhanded methods for career advancement. His ambition previously manifested in engineering the demotion of the Soyokaze's former captain, an action indirectly leading to the crew's demise and the captain's subsequent suicide.

Fuji advocated decisive military action against the Raalgon Empire, believing the United Planets Space Force possessed superior morale, leadership, and technology to crush what he perceived as a disorganized enemy weakened by internal power struggles. This perspective drove his push for a full-scale preemptive attack.

He harbors significant disdain for Captain Justy Ueki Tylor, viewing him as lacking the prowess, intelligence, and respectability expected of a military officer. Collaborating closely with Admiral Mifune, he repeatedly attempts to eliminate Tylor or place him in perilous situations, including orchestrating an assassination attempt via super-ballistic missile and later hiring pirates to destroy Tylor's ship, the Soyokaze; both plots ultimately failed. His underlying fear and guilt regarding his role in the previous Soyokaze captain's fate surfaced upon observing Tylor in possession of that captain's pipe, prompting him to hastily rescind the Soyokaze's demotion order.

A shift occurs as the series progresses, influenced by Fleet Admiral Mifune's explanation of Tylor's unconventional value. Fuji develops a reluctant respect for Tylor, moving from outright hostility to a begrudging acknowledgment of Tylor's impact.