Jurgens is the captain of the Izumo, a powerful battleship belonging to the United Federation. He is a military man through and through, characterized by his stern demeanor, his uniform, and his neatly kept mustache. In his first appearances, he is portrayed as a dutiful, if often dissatisfied, antagonist. He is frequently seen complaining about his assignments, and his initial mission is to shoot down the Gekko, the ship of the insurgent group Gekkostate. His failure in this task results in him being temporarily stripped of his command.

Despite his early role as an adversary, Jurgens possesses a strong moral compass and a sense of honor that becomes more apparent as the story progresses. He carries a deep, personal sorrow, as it is revealed that he lost his wife and two daughters in a past civil war. This tragic background gives him a unique perspective on the conflict and the suffering it causes. His motivations shift from simply following orders to actively seeking the truth. After reading an underground magazine called ray=out, which exposes corruption within the Federation, and personally witnessing the horrifying results of military experiments, he begins to question the side he fights for. This search for answers ultimately drives him to commit an act of profound principle.

Jurgens's role in the story evolves significantly from a conventional antagonist to a crucial ally. After regaining command of the Izumo, he is ordered to assist in a mission that opens his eyes to the true nature of the conflict. Convinced that the Federation is in the wrong, he makes the pivotal decision to defect. In a striking display of leadership, he presents the truth to his entire crew of eighty-eight members, and not a single one abandons him; together, they join forces with the Gekkostate. In the final battle, he demonstrates his nobility by using his ship, now renamed the Super Izumo, as a diversionary decoy, sacrificing it to allow the Gekko and its crew to reach the protagonists and save them.

His key relationships are defined by mutual respect. He shares a close bond with his adjutant, Maria Schneider, who is his trusted second-in-command. He also serves as a mentor-like figure to Dominic Sorel, another officer in the Federation, with the two often quarreling but building a deep, fatherly connection. His relationship with Holland, the leader of Gekkostate, transforms from that of hunter and hunted to two captains fighting side-by-side as equals.

Throughout the series, Jurgens develops from a man forlornly following orders into a proactive leader driven by his conscience. His most notable act of development occurs not in combat, but in the aftermath of the war. Haunted by the suffering of the children he witnessed and feeling a responsibility to atone for the destruction caused by adults, Jurgens decides to adopt the surviving orphans from the Ageha Squad, a group of young soldiers. As a captain, his abilities lie in command and strategy, effectively piloting the massive Izumo-class battleship and leading his crew with a combination of authority and earned loyalty.