Kazuo Ushiyama occupies the role of Maintenance Unit Operator for the organization Gutsy Geoid Guard, later known as the Gutsy Galaxy Guard. His duties encompass technical support and maintenance for the group's mechanized units and systems.

He takes active combat roles in critical field operations, including co-piloting the mechanoid GaoGaiGar during Episode 15 alongside other crew members. His technical support extends to developing and deploying specialized equipment like the Dividing Driver, a tool designed to minimize collateral damage in combat.

The character continues into later narratives, appearing in the OVA series *GaoGaiGar FINAL* as part of the Gutsy Geoid Guard. His presence is further referenced in the *GaoGaiGar vs. Betterman* storyline, set years after the original events.

Kazuo Ushiyama shares a familial connection within the series as the eldest brother of Sueo Ushiyama, a classmate of Mamoru Amami. Sueo idolizes Kazuo's role in the defense organization and aspires to similar duties, eventually joining the Maintenance Division of the next-generation Gutsy Global Guard as an operator. This establishes Kazuo's professional lineage and influence on subsequent characters.