Ryoma stands as a core warrior of the Fuma Clan alongside Kojiro. Wielding the sacred sword Seiranken marks him as a chosen Cosmo Warrior, destined for the recurring Sacred Sword War against the Chaos Warriors. His combat blends traditional ninja techniques with advanced psychic abilities, notably the energy-projecting Fuma Shikyoken. Surviving the massacre of his clan by Chaos forces with Kojiro and a few others, Ryoma becomes pivotal in the conflict to reclaim the sacred swords and confront the Chaos Emperor. During the Sacred Sword War Chapter, he pragmatically allies with former enemies like Musashi Asuka, setting aside their clans' historical rivalry. Stoic and duty-bound, Ryoma frequently invokes "Shinobi Law" as his guiding principle. This strict discipline sparks internal conflict when faced with humanizing influences such as Ranko Yagyu's attempts at kindness and emotional connection. Ryoma participates in key battles against Chaos warriors, leveraging tactical acumen and sacred sword powers. Themes of destiny and cosmic reincarnation central to the Sacred Sword War shape his journey, culminating in confrontations that reveal the conflict's cyclical nature. His arc continues into the live-action adaptation, where expanded focus on his interactions and combat role further explores the internal struggle between his identity as a tradition-bound warrior and the emerging recognition of his own humanity.