Dr. Yamanoue, Director of the Ministry of Science and a roboticist, designed the physical body of the robot Jetter Mars in 2015 on an artificial island in Tokyo Bay, intending it as a powerful weapon for warfare. Unable to develop functional artificial intelligence himself, he enlisted Dr. Kawashimo to create the AI. Upon activation, Yamanoue named the robot after the Roman god of war, reflecting its militaristic purpose.

He views robots strictly as military tools and insists on rigorous combat training for Mars. This philosophy frequently clashes with Dr. Kawashimo, who advocates for Mars to develop compassion and humanity. Throughout the series, Yamanoue persistently pushes Mars through combat simulations and tests to mold him into a "war machine," though Mars' playful and disobedient nature often thwarts these efforts.

During a test of a gravity weapon, an accident kills all participating scientists. Yamanoue survives but is captured and taken to an unspecified foreign country, forced to work under a dictator. Despite captivity, he eventually finds an opportunity to send a message to Mars, revealing he is alive.

Dr. Yamanoue's character design resembles Dr. Tenma from *Astro Boy*, reflecting the series' initial concept as a sequel or remake. His role as a creator prioritizing military utility over ethical considerations drives central conflicts regarding Mars' development and purpose. In official media, Yamanoue makes a brief, narratively insignificant cameo in a 1977 *Black Jack* manga chapter. His foundational role in Mars' creation, subsequent disappearance, and captivity form his complete character arc.