Exkaiser commands the Space Police Kaisers, an intergalactic peacekeeping force of energy-based beings hailing from Kaiser Star. To conceal his presence on Earth, he morphs into a sports car owned by the Hoshikawa family, covertly communicating with the young Kouta and their dog Mario. His armored physique integrates a blue chestplate that shifts into a roaring lion’s head via a "Breast Change" mechanism, amplifying his combat prowess.

A master of tactical warfare, Exkaiser unleashes attacks like the Jet Boomerang, Spike Cutter, and Flaming Nova, supplemented by searing energy beams from his chest or eyes. He ensnares foes with retractable belts from his forearms and mends technology using a Forming Beam projected from his helm. Supported by auxiliary units King Roader and Dragon Jet, he merges into advanced configurations: King Exkaiser (trailer fusion), Dragon Kaiser (jet fusion), and Great Exkaiser (dual fusion), wielding upgraded armaments such as the Kaiser Sword and Thunder Crash finisher.

Tasked with thwarting the treasure-hunting Geister pirates, Exkaiser upholds an unwavering code against lethal force. This ethos defines his climactic duel with Dino Geist, who self-destructs to evade justice, prompting Exkaiser to ponder the nuances of righteousness. Key missions involve unearthing the ancient Kizer Sword within Peru’s Nazca Lines—a relic tied to his predecessors—and forging bonds with Kouta, whose humanity reshapes his worldview. Their poignant farewell concludes with Exkaiser vowing silent guardianship from the stars.

Sequels expand his legacy: In *Brave Saga 1*, he allies with warriors like Armed Fighbird to repel resurgent Geisters and the shadowy Nightmare. *Brave Saga 2* sees him nearly obliterated during the Demen Tribe’s assault on Space Police headquarters, reaffirming his resilience as a multiversal sentinel.