Tasuku Ryūenji, a 13-year-old seventh grader at Aibo Academy, embodies unwavering dedication to justice as a member of the Buddy Police. His striking appearance features white and blue hair—sleek on the right, sharply spiked on the left—paired with piercing pinkish-red eyes. His signature orange Buddy Police vest, adorned with the group’s emblem and shoulder pauldrons, overlays a teal jumpsuit stretching from wrists to lower knees, layered atop a black shirt. Orange fingerless gloves and elbow pads complete his combat-ready look. In school attire, he wears a blue coat with dark blue and red accents, a red-striped blue tie, a crisp white shirt, blue pants, and brown shoes.

Tasuku’s partner, Jackknife Dragon, a green dragon from Dragon World, shares a bond deeper than kinship, each prepared to sacrifice for the other. Their Buddy Skill, Sky Circle, grants Tasuku flight via glowing discs beneath his feet, trailing emerald mist as he soars.

"The Disaster," a pivotal event from his past, forged his ironclad resolve to protect others, often driving him to act alone, even against orders. This conviction once led him to adopt the alias "Purgatory Knight" and ally temporarily with the Disaster Group, pursuing justice through aggression. Recognizing the harm of this path, he reclaimed his original ideals, later rising to Commissioner within the Buddy Police—a testament to his growth and earned trust.

His bond with Jackknife Dragon evolves into a transformative partnership, culminating in the dragon’s ascension as Star Dragoner, Jackknife, mirroring their shared journey. Tasuku’s story intertwines resilience, unyielding justice, and the unbreakable alliance with his Buddy, defining his legacy as a protector.