Fudo no Ryoma stands as one of three primary protagonists. He is a member of the Hagakure ninja clan, part of the trio of groups called The Shadow Warriors, hunted by Oda Nobunaga's demonic forces in the Sengoku period. As the sole survivor of the Hagakure clan's destruction, he wields a holy halberd, one of three mystical weapons prophesied to defeat Nobunaga. Following his clan's massacre, he forges an alliance with Ayame of the Kasumi clan and Sakon of the Hyuga clan, both also sole survivors bearing sacred weapons.

His past includes witnessing the deaths of those close to him during the attack on the Hagakure clan, though these losses receive less narrative focus than those of his allies. Characterized by loyalty and kindness, Ryoma demonstrates unwavering commitment to his companions and their shared mission against Nobunaga. He fights in the final confrontation where the combined power of the three holy weapons defeats Ranmaru, Nobunaga's demonic advisor who orchestrated the clans' destruction. This battle reveals Ranmaru himself forged the holy weapons centuries earlier as part of a scheme to open a gate to the underworld, inadvertently creating the means for his own defeat.

Details regarding the character's appearances or development in other media such as OVAs, spin-offs, or alternate continuities stem solely from the film adaptation compiling the original OVA series.