Ryōma, a Fuma clan ninja entrenched in a centuries-old vendetta against rival factions, narrowly survives the Chaos faction’s obliteration of his village after the Yasha clan’s downfall. This catastrophic betrayal propels him into the Sacred Sword War, uniting with survivors like Kojiro to thwart the Chaos Warriors and their emperor’s quest to seize ten mystical blades for dominion.

Wielding the Sacred Sword Seiranken as a Cosmo Warrior, Ryōma employs calculated precision in battle, coordinating with allies to dismantle Chaos’s advances. The war exposes hidden truths—the swords’ latent purpose and a millennia-spanning cycle of conflict—cementing his resolve to end the struggle while honoring the Fuma legacy.

Prequel OVA events cast him in the Fuma-Yasha clash, spearheading Hakuo Academy’s defense and solidifying his bond with Kojiro as a linchpin in ninja warfare. His tense rapport with rivals like Musashi Asuka oscillates between clashing blades and uneasy alliances, particularly when Chaos’s threats demand reluctant unity.

Consistently portrayed across manga and adaptations, Ryōma’s narrative centers on tactical prowess and clan loyalty, eschewing personal backstory beyond collective Fuma trials. His focus remains unshaken: dismantle adversaries, secure the Sacred Swords, and sever the war’s endless recurrence.