Dr. Ochanomizu succeeds his predecessor and former colleague Dr. Umataro Tenma as Minister of Science. A short, portly man in his mid-60s, he has a prominent nose and receding curly white hair framing his face, usually dressed in laboratory attire or formal clothing. In his youth, he displayed a taller, slimmer build with black curly hair.

During graduate studies, he shared a room and lab partnership with Tenma, collaborating on robotics projects including the creation of the AI robot "Six" at their private facility, Lab 7. He champions robot rights and justice through policies like the Robot Bill of Rights, granting autonomous robots equal status to humans. His personality merges sharp intellect with fiery passion, though earlier portrayals depict an explosive temper that later softens. He maintains a critical yet reform-focused perspective toward Tenma, condemning his abuses while advocating for his redemption.

In most narratives, he rescues Astro from abandonment or enslavement—notably intercepting him from Hamegg's robot circus—becoming his legal guardian and primary paternal figure. He reactivates Astro after Tenma deactivates or rejects him, then integrates him into society by enrolling him in school and crafting a robotic family unit complete with parents and a sister named Uran. Some adaptations, like the 2003 series, show him directly adopting Astro and Uran, housing them in his residence.

His technical innovations include designing advanced robots like Uran and supplying Astro’s blue energy core in the 2009 film, derived from positive-energy meteor elements. As Science Minister, he directs Astro’s missions to defend humanity and mediate human-robot conflicts, exemplified in "Shinsen-gumi" where he backs Astro’s clashes with threats like the anti-human Blue Knight. His overarching legacy promotes human-robot coexistence, viewing Astro as essential to this future.