OVA
Description
Amano Jaku is a hybrid entity, part human and part demon, originally of the Jūjin man-beast race. Banished from the demon realm to Earth as punishment for transgressions against the Great Elder involving the Elder's granddaughter Mimi, this exile sets the stage for his centuries-long mission. Tasked by the Great Elder, Amano Jaku spends three hundred years searching for the Chōjin, a prophesied supreme being destined to unite the human, demon, and beast-man realms during a convergence event occurring every three millennia.

His initial portrayal diverges across media: the manga depicts him as manipulative and lecherous, deceiving women into sexual encounters by claiming his semen offers protection against demons. Conversely, anime adaptations present a more focused, nobler figure committed to his mission, though still grappling with moral ambiguities. During his quest, Amano Jaku identifies human high school student Tatsuo Nagumo as the vessel for the Chōjin's rebirth. He becomes Tatsuo's protector against antagonistic forces like the demon Suikakujū and his allies, who aim to kill the Chōjin to prevent unification. This conflict escalates as supernatural entities invade the human world, leading to violent confrontations. Amano Jaku operates alongside his sister Megumi, a nymphomaniac whose characterization varies—displaying malicious traits in the manga but greater empathy in the anime—and his loyal companion Kuroko.

Amano Jaku's relationship with Mimi, the Great Elder's granddaughter, remains crucial. Her supernatural ability to project visions of the future during intimacy provides critical guidance for his mission, underscoring his connection to the man-beast realm's political and spiritual hierarchies, despite the strain of his exile.

As the prophecy unfolds across OVAs and films, Amano Jaku witnesses the Chōjin's emergence and the subsequent apocalyptic transformation of the world. The Overfiend's ascension triggers catastrophic mergers of the realms, causing widespread devastation. During these events, Amano Jaku confronts personal betrayals and ideological disillusionment when the promised unification results in chaos instead of harmony. His journey includes navigating post-apocalyptic landscapes, such as leading survivors toward Osaka for a final confrontation in "Inferno Road," where he battles adversaries like Yoenki, Suikakujū's vengeful sister transformed into a destructive entity.

His character arc culminates in questioning the prophecy's validity and his own role in its fulfillment. Faced with irreversible consequences and the suffering wrought by the Chōjin, Amano Jaku shifts from unwavering belief to a resigned, pragmatic outlook. This evolution is marked by his efforts to protect remaining allies amidst ongoing turmoil, leaving his ultimate fate unresolved following the climactic battles in Osaka.