Isuke Fuma, once heir to the Fuuma clan’s legacy as its tenth-generation leader, navigates a fractured existence between ruthless duty and fragile humanity. Born alongside twin brother Isame into the secretive ninja tribe devoted to reviving the serpent deity Orochi, his childhood was steeped in merciless tradition. The clan’s brutal rite of passage demanded he execute his father, Eishirou—an act that shattered his psyche and estranged his grieving mother. Forged by this trauma, Isuke and Isame merged their identities as Kotarou Fuuma, a namesake echoing their entwined leadership, and covertly purged dissenters while feigning the clan’s demise. Their machinations led them to eliminate Kumo Taiko and Kumo Koyuki, guardians of Orochi’s vessel, before Isuke infiltrated the remaining Kumo heirs as "Shirasu Kinjo," a housekeeper masking his surveillance of Tenka, Soramaru, and Chutaro.

Yet beneath his calculated facade, bonds formed. The Kumo siblings’ unexpected kindness thawed his disciplined resolve, intertwining his mission with conflicted affection. Despite this, he manipulated their trust, framing Tenka as Orochi’s host and betraying them in the climactic clash. Victory left him hollow: after the deity’s fall, he hurled himself from a cliff, only to endure, physically scarred yet emotionally tethered to those he deceived. Returning to the Fuuma, he carried the ghost of that borrowed life—a stark duality marked by his transformed appearance, white hair and violet eyes replacing his original black hues, symbols of sacrifice and fractured identity.

His words betray yearning—a wish for tranquil days with family, memories of the Kumo household likened to a fleeting, radiant dream. Each choice, from patricide to paternal deception, etches his tragedy: a man cleaved by loyalty and loss, forever balancing the ninja’s blade against the weight of what he dared to love.