Sometime in the 17th century, Amano Jyaku began his search for the Choujin in the human realm - it is not known whether Megumi Amano or Kuroko accompanied him. Also, during this time, he must have encountered Suikakujyu and started of his infamous rivalry with him.

Legend has it that the human race is not the only dominant civilization living on Earth. Two other races exist in this world: the Makai (a demon race) and the Juujinkai (a half-man, half-beast race). Once every 3,000 years, a supreme being known as the "Choujin" (Overfiend) will emerge and bring balance to all three realms on Earth. In present-day Japan, after 300 years of endless searching, a Jujinkai named Amano Jyaku has discovered the presence of the Choujin inside high school slacker Tatsuo Nagumo. But now, Amano, along with his sister Megumi and their sidekick Kuroko, must protect Nagumo and his new girlfriend Akemi Ito from the Makai, who believe that Nagumo is not the Choujin, but an evil entity bent on destroying all living beings on Earth. 

[Wiki (jp)](https://ja.wikipedia.org/wiki/西村朋紘) | [Wiki (en)](https://en.wikipedia.org/wiki/Tomohiro_Nishimura)

[French Wikia](http://fr.wikipedia.org/wiki/William_Coryn)

Summary of Choujin Densetsu Urotsukidouji.

Twenty-five years ago, the world was annihilated. With the coming of the Overfiend, God of all Gods, the human, demon, and beast realms collapsed together in chaos. With the promise that he would be born in 100 years to re-create his failed world, the Overfiend settled back to sleep within his mother's womb. 
But something has gone terribly wrong... 
Now the Overfiend is born prematurely and awaits the coming of his natural the enemy, the Lord of Chaos. His only hope for survival are Amano Jyaku and his sister Megumi. But destiny has moved in ways that even the Overfiend could never predict, as a new race of half-breed demon beasts has evolved. 
As Amano travels to the kingdom of Azuma to investigate the appearance of the Lord of Chaos, he is swept up in the world-conquering schemes of Caesar, Azuma's dictator. 
Against the backdrop of a demon beast slave revolt and the return of the diabolical Munhihausen, only Amano and the demon beast Buju can save the world from another fiery destruction. With the fate of the earth and its inhabitants hanging in the balance, all wait to see what the coming of the Lord of Chaos will bring...

There is a legend that in 3,000 years an unbeatable god of the demon world known simply as the Overfiend will be resurrected into the body of a young man. Amano, a half demon, travels to the human world to find the Overfiend before his pure demon rivals find the god-like being. Unfortunately, he keeps on being side-tracked by Tatsuo Nagumo, a shy, bumbling lecherous teen, and future classmate, that keeps finding himself in all sorts of trouble with beings from the Demon Realm. If Amano can’t find the host of the Overfiend, how is going to be able to protect him from the clutches of the oncoming demon horde? (Source: Fakku)

Directly following the conclusion of Urotsukidoji III, the survivors of the Azuma kingdom genocide travel aboard a futuristic tank with Osaka as the destination. There, they plan to face both the Overfiend and their own fates as well. Along they way, the stumble upon a civilization beyond imagination, where children cruely rule over the adults. It is up to Amano Jyaku to save his friends from this sinister land and its evil ruler, Ellis. Shortly after their encounter, Sui Kaka Ju's sister Yoenhime summons Munhihausen, who transforms her into the menacing Yoenki. At last, she is strong enough to reap revenge on Amano for killing her brother. But Munhihausen has his own hidden agendas. The Urotsukidoji legend will finally reach its climax in Osaka, when Kiojo, the sweet and innocent Himi, and the Chojin meet face to face. 

Only one episode of this was partially completed, the released version containing numerous examples of animation that is missing in-between frames. The story as such concerned the arrival of the real Chojin as he/she (a hermaphrodite) makes moves to wipe out all life on Earth. 
Interestingly, the setup for the show was far more heavily connected with the first two, more popular, chapters in the Urotsukidoji saga, with appearances by Nagumo and Akemi (unseen since the early episodes of Part III), and redesigned character models that more closely resembled the earlier episodes. Some of the less popular characters introduced in chapters III and IV, particularly Buju, were nowhere to be seen. Nevertheless, such strategies did little to get this final saga off the ground and the story was shelved. 
(Source: Wikipedia)

Nazi Germany - 1944: As American bombers soar towards Berlin, a revolting Satanic rite takes place below - Hitler and his minions are using the monstrous Nazi Death Rape Machine to render the dimensional boundaries separating the Human World from the World of Man-Beasts and the World of Monster Demons. Dr. Munhihausen Sr.`s life work is about to come to fruition - the conjuring of the Overfiend! 
Cut to modern day Tokyo - Munhihausen Jr. searches for a monster with strength enough to conquer the omnipotent Overfiend. Since legend says that he who kills the Overfiend will rule all three worlds forever, Munhihausen is determined to slay the Overfiend and assume complete control over all three dimensions. His efforts seem fruitless - until Nagumo`s cousin Takeaki, infused with Nagumo`s blood after an accident, begins to develop monstrous powers. 
As Man-Beast Amano Jyaku and his sister Megumi, together with faithful accomplice Kuroko attempt to thwart Munhihausen`s evil plan, nothing seems likely to prevent Munhihausen, descendant of a race of brutal tyrants, from enslaving the world under his despicable rule!

During World War 2, the Nazis attempted to breach the barriers between the three worlds. They failed then, but a Dr. Myunihausen (Munchausen?) tries again, through the manipulation of Nagumo's brother Takeaki. His goal? To have the Chojin replaced. 
As Takeaki is injured in the approaching flight, Nagumo donates some of his blood to save his life, thus infusing Takeaki with the powers of the overfiend. And the results might be too much for Tokyo, perhaps even the overfiend himself, to bear. 
(Source: themanime.org)

An immortal beast-man of supernatural lusts, Amano Jaku escapes prison to gratify his appetites at Meishin College. But the campus is not just a hotbed of luscious coeds &ndash; it&rsquo;s the breeding ground of a hideous monster! The Ultra God is Amano Jaku&rsquo;s nemesis, a vile killing machine, and the ancient harbinger of the coming apocalypse. Now, immortals will clash in a battle that will bathe the Earth in innocent blood! 
(Source: AniDB)

Amanojaku