Kōtarō Taiga serves as the commander of the Earth Defense Force Gutsy Geoid Guard, later renamed Gutsy Galaxy Guard, while publicly holding the position of president of the Space Development Corporation. His dual role places him at the center of humanity’s defense against the Zonders, as he holds the authority to approve critical operations such as the Final Fusion of GaoGaiGar and the deployment of high-risk weaponry like the Goldion Hammer. Before assuming this post, Taiga was a member of the special task force ID5, where he operated under the code name Gold Tiger, an experience that earned him the respect and practical combat skills he later brought to GGG.

Taiga is defined by a strong sense of justice, a calm and decisive temperament, and an unwavering trust in the people under his command. He believes that even when resources or technology fall short, courage can bridge the gap, a philosophy he often expresses and embodies. His leadership style inspires deep loyalty from both human personnel and the Brave Robots, who see him as a reliable and fatherly figure. Despite his demanding responsibilities, he maintains an approachable and warm demeanor, with a noted charm that makes him unexpectedly popular among female staff.

A family man, Taiga is married to a former Miss Katsushika winner and has two daughters, though he rarely speaks of his private life. Among his personal traits is a fondness for golf, which he uses not only for relaxation but also as a covert skill: he is proficient in a close-quarters combat technique called the Titanium Head Driver, employing a golf club to incapacitate opponents. As the story progresses, Taiga’s role evolves from a strictly Earth-bound commander to an interplanetary leader. In the sequel OVA, he temporarily steps down as GGG chief to raise concerns about the dangers of The Power, but later returns to lead the organization in its off-world mission, demonstrating his enduring commitment to protecting humanity and his belief in the strength of his team.