OVA
Description
Dr. Kōzaburō Nanbu is the brilliant scientist and founding leader of the Science Ninja Team, serving as the team's creator, mentor, and primary support from the organization's headquarters. A genius-level intellect, he is a graduate of Oxford and Cambridge Universities and holds the position of an honorary professor at the University of Tokyo while also serving as the director of the ISO Mantle Plan. As a high-ranking figure within the International Science Organization, he was one of the first to recognize the global threat posed by the terrorist group Galactor and was instrumental in formulating the strategic response that led to the team's formation.

Dr. Nanbu is a paternal figure to the five young members of the team, acting not only as a commanding officer but as a surrogate father who cares deeply for their well-being. His personality is a blend of stern professionalism and genuine compassion. While he is capable of making difficult and sometimes coldly logical strategic decisions for the greater good, his primary motivation is the protection of Earth and the safety of his young charges. He is often shown observing the team's battles from a monitor, providing tactical guidance, and in some instances, directly confronting the Science Ninja Team's Commander Contrarian tendencies, insisting on discipline and strategic control.

Within the narrative, Dr. Nanbu operates as the mission controller and technological benefactor. He is responsible for developing the team's arsenal, including their signature bird-style battle suits and the advanced combat vehicle, the God Phoenix. He also developed the unique martial art known as Science Ninja Technique that the team employs. His role is crucial as the link between the political authority of the International Science Organization and the active field operations of Ken Washio and his teammates. He often assigns missions and provides the necessary intelligence and equipment for them to succeed.

His most significant relationships are with the team members. He has a particularly close bond with Joe the Condor, the team's second-in-command. After Joe's parents were killed by Galactor, Dr. Nanbu rescued the boy and raised him as his own son, giving him the name Joe Asakura to hide his identity from the organization. This creates a deep, father-son dynamic between them. He also serves as a primary authority figure for the leader, Ken the Eagle, who sees Dr. Nanbu as a surrogate parent due to the disappearance of his own father.

Dr. Nanbu's character undergoes significant development across the series and its sequels. In the original series, he is a constant presence, guiding the team from behind the lines. In the first sequel, Gatchaman II, he deliberately fakes his own death to counter an assassination plot by Galactor, demonstrating his willingness to sacrifice his personal life for the sake of the mission. This personal cost becomes more tragic in the subsequent series, Gatchaman Fighter, where he is captured by the enemy and, after enduring brutal torture, is killed for real, marking a profound turning point for the team and raising the stakes of their conflict to a deeply personal level.

His notable abilities lie not in physical combat but in his exceptional scientific and strategic genius. He is the inventor of the Science Ninja Team's advanced technology, including the transformation systems that allow their civilian vehicles to convert into combat-ready machines. His strategic mind is considered his greatest weapon, as he is consistently able to analyze Galactor's complex and often bizarre attacks, deduce their weaknesses, and formulate the counter-strategies that the team executes in the field.