OVA
Description
Amano Jyaku is a demon/human hybrid originating from the Man-Beast realm (Jujinkai), though the manga initially presents him simply as a half-breed between demons and humans without a distinct third realm. Banished to Earth by the Great Elder for misdeeds primarily involving the Elder's daughter, Mimi, Amano is tasked with locating the Chōjin (Overfiend). This all-powerful entity is prophesied to unite the three worlds—human (Ningenkai), demon (Makai), and Man-Beast—every 3,000 years. His centuries-long mission begins in the 17th century.

In the manga, Amano exhibits a sociopathic and lecherous personality, frequently manipulating women into sexual encounters under false pretenses, such as claiming his "magical sperm" offers protection. He displays morally reprehensible behavior, casually discarding a rescued infant into a river. Operating as a self-serving Villain Protagonist, he shows minimal empathy or heroic inclination unless it serves his interests. His story concludes with him ambushed and killed by demons, his body discovered atop a pile of corpses.

The anime adaptation significantly alters his characterization through Adaptational Heroism. Here, he embodies an Anti-Hero initially driven by faith in the Chōjin's prophecy bringing peace. He displays loyalty and protective instincts, particularly toward the human hosts of the Chōjin, Nagumo Tatsuo and Akemi Ito. His personality includes moments of abrasiveness (increasing in later OVA sequels), but he consistently demonstrates a "Jerk with a Heart of Gold" archetype, intervening to defend others despite his cynical exterior. Unlike the manga, he survives the series' events.

Key relationships define his journey. Mimi Tenno, the Great Elder's granddaughter, is his lover; her orgasms grant prophetic visions crucial to his quest. His sister, Megumi Amano, aids him but exhibits differing traits between media: the manga depicts her as malicious and manipulative, while the anime portrays her as kinder and more empathetic. His central rivalry is with the demon Suikakuju, who seeks to kill the Chōjin to preserve the demon world's autonomy. This conflict culminates in Suikakuju triggering the Great Kanto Earthquake of 1923 during a failed attempt to destroy the Chōjin, an event Amano inadvertently thwarts.

Amano's core conflict revolves around the Chōjin prophecy. After centuries of searching, he initially mistakes human Norikazu Ozaki for the Chōjin, leading to Ozaki's demise. He later identifies Nagumo as the true vessel, becoming his protector. However, the prophecy's promised utopia proves false; the Chōjin's emergence brings apocalyptic devastation, merging the three worlds into a nightmarish wasteland. This betrayal shatters Amano's faith, rendering him a disillusioned witness to the suffering inflicted on humanity.

In the final OVA installments, his role shifts to observing the Overfiend's tyranny and the rise of its antithesis, the Lord of Chaos (Kyo-O). The saga concludes with a temporal reset: after a cataclysmic battle, Amano awakens in 1988 Osaka at the exact moment his quest began, condemning him to relive the cycle. He reacts with despair, symbolized by his agonized shout to the heavens.