Gorō Ōtaki, widely called "Mr. O," directs and owns Otaki Factory—a robotics facility in Chiba, Japan. This world-renowned scientist holds numerous international patents. His obsession with UFOs and unidentified creatures fuels his mission to protect Earth from perceived paranormal threats, driving Otaki Factory’s creation of the defense mecha Jet Jaguar against extraterrestrial or interdimensional dangers.

Operating with a small team—engineer Yun Arikawa, technician Haberu Kato, and receptionist Satomi Kanahara—Otaki funds and oversees Jet Jaguar’s development and upgrades despite the factory’s modest resources. When kaiju threats escalate, he mobilizes the team, often charging into danger alongside Yun and Haberu. During Jet Jaguar’s inaugural field test against Rodan, Otaki pilots the mecha personally, delivering Shakespearean monologues and kabuki-inspired theatrics mid-combat. The battle damages Jet Jaguar and injures Otaki, prompting a shift to autonomous AI operation.

Eccentric yet ingeniously pragmatic, Otaki blends conspiracy theorist tendencies, antiquated speech, and a clouded demeanor with undeniable technical expertise—his patents sustain the factory financially. He reveals unexpected strategic depth, quoting Sun Tzu and weaving Buddhist rituals into crises, like praying to various Buddhas or directing Jet Jaguar to honor the Six Directions for a superhero pose. Though originally fixated on alien invasions, his focus pivots to kaiju, indirectly validating his preparedness.

Throughout the conflict, Otaki spearheads Jet Jaguar’s critical advancements: integrating weapons like the Anguirus Spear, enhancing mobility via wheeled and later extended legs, and implementing Yun’s "Protocol to make Jet Jaguar Invincible." Despite his age, he joins field operations, traveling to Tokyo for the final clash against Godzilla Ultima. His leadership and resources enable Jet Jaguar’s evolution into Jet Jaguar PP, which neutralizes Godzilla and averts global catastrophe at the cost of the mecha’s existence.