Ryuuma, also known as Ryōma, is a core member of the legendary Fuuma ninja clan. He bears the epithet "Dokugan Ryu" (One-Eyed Dragon), a title referencing his missing eye and shared with the historical figure Date Masamune due to this physical characteristic. As a Fuuma warrior, Ryuuma wields exceptionally powerful psychic abilities, considered the strongest within his clan. His demeanor reflects focus, respect, and a strong sense of duty towards his clan's legacy and commitments.

He arrives at Hakuo Academy alongside fellow clan members Kouu and Ryuho in the third episode of the initial OVA arc, significantly bolstering the Fuuma's forces against their rivals. Ryuuma plays a pivotal role in reigniting the centuries-old conflict with the Yasha clan by formally issuing the challenge that escalates hostilities, directly setting the stage for the extended ninja war depicted across the series.

Following the resolution of the Yasha conflict, Ryuuma continues his involvement in subsequent events. He participates in the Sacred Sword War arc, aligning with the Cosmo Warriors alongside Kojirou, Musashi Asuka, and others. After this conflict concludes, Ryuuma and Kojirou temporarily disappear for three months. They return during the Fuuma Rebellion arc to confront the traitorous New Fuuma Clan led by Shimon. Alongside surviving clan members like Kirikaze, Shoryu, and Ryuho, Ryuuma engages in the internal struggle to protect the clan's integrity and quell the rebellion.

Ryuuma's presence and actions are consistent across all official animated adaptations: the *Yasha-hen* OVA (1989), the *Seiken Sensou-hen* OVA (1990), and the concluding *Fuma Hanran-hen* OVA (1992). He also appears in the live-action drama adaptation of the *Yasha Chapter*.