Zuru Oozora, also identified as Yuuzuru Oozora in Japanese media, is the son of Dr. Maizuru Oozora, the creator of the Death Medarots. This connection fuels his deep resentment toward the emotionless machines, blaming them for his father's neglect and the resulting damage to his family.

Publicly, Zuru cultivates an image as a shy, quiet, and academically focused student, befriending classmates such as Ikki and Arika. He deliberately masks his Robattle abilities, employing an unassuming DonDoguu-class Medarot in social situations.

Secretly, he operates as the cloaked vigilante "Mystery Medarotter," dedicated to destroying all Death Medarots. In this role, he primarily wields the Dorcus-class Medarot (localized as Roks), treating it as a disposable instrument. His ruthless tactics include unprovoked attacks on Death Medarot users, prompting observers to question if his methods differ morally from his targets.

Later, he temporarily adopts the Death Medarot Excise and repurposes his DonDoguu's Medal into a Tyrrellbeetle-class Medarot for his vigilante activities. While his crusade originates in personal trauma, interactions with Ikki and Metabee challenge his perception of Medabots as mere tools.

Zuru gradually develops loyalty toward his primary Medabot, Dorcus, beginning to see it as a companion. This growth culminates when he voluntarily reveals his secret identity to both allies and antagonists during a critical confrontation to save Arcbeetle Dash, demonstrating his commitment to teamwork and ethical Medafighting.

His character arc resolves with a shift from vengeance-driven vigilantism to protecting Medabot users through cooperation, embracing principled allyship over isolation.