Tsukiyomi, a scholar from Ise presumed dead until his survival under mysterious circumstances came to light, emerges as the primary antagonist orchestrating events involving the destructive Shinobi entities. Once mentoring Ame during her childhood, he instructed her in the use of the Holy Weapon Giga Road—a critical weapon against the Shinobi threat. Despite their bond, he manipulated the crisis by permitting the Shinobi’s annihilation of Ise, advancing his hidden ambitions.

Driven by ambitions to harness the Shinobi’s power to reshape the world, he views himself as transcended humanity through Shinobi cell integration into his body. Embodying the Mad Scientist archetype through experiments fusing human and Shinobi biology, he operates as a Treacherous Advisor, twisting his past ties with Ame to further his schemes while dismissing her mission as mere personal vengeance.

Tsukiyomi evolves from a respected scholar to a self-declared deity, fueled by a god complex and an obsession to dominate the Shinobi’s destructive power. His arc climaxes in a final showdown where his machinations unravel, though his ultimate fate remains shrouded, with no expanded accounts in spin-offs or ancillary media.