Not much is known about these beings who have been exalted in a pedestal of godhood and immortality. Their very existence represented the various evolution of the world and through them, the knowledge of fate was known as a mere whim unchallenged and beyond that of any understanding – at times, even the yōkai have no idea of their own limits which only furthers the mystery which allures men of all stature, no exceptions.
There are indeed various kinds of yōkai written across the olden scrolls of yore. They all command elements which comprises that of the world in which no human could do. The well-known are that of the Oni, ferocious beasts with unparalleled strength that have the taste for human flesh, Kitsune known for their tricks and deceptive lores, Tengus who are harbingers of misfortune and command horrendous gust of wind, Kappas who inhabit rivers that drown men to its depth, and so on... Each unique from one another, have their own customs, leading to a belief they were a civilization of different proportions. Therefore, they were feared for their reputation, but all of them complete a circle of balance they hoped never to be broken, which is maintained by mutual respect.
Humanity embraced their presence much like that of a wind that gives life yet can also bring scornful vengeance If taken for granted. To mortals, they were the explanation of many natural occurrences that the mere human mind could not comprehend. And because of that, a coexistence existed between them and the humans, during those times, harnessed a delicate bond composed of fervent belief, respect, fear, and a keen sense of friendship. This created an era of fantasy and mythical proportions centered in the ideology of ancient spirits and demons.
Yet, there is as they say… things are meant to END.
Time moved on which provided many doors for men to develop a separate identity apart from such mystifying lore. This lead for yōkai to be seen as a threat to a new world order founded by the Tokugawa lineage. They made sure that many memories of old Japan were wiped clean. They had established nationwide yōkai hunts through the pretense of eradicating the darkness known as yōkai that firmly guides this country to destruction. For them, these ancient spirits were reminders of a crude, barbaric, primitive Japan, and like many other relics of the past, they had to be dealt with in the most efficient manner, elimination.
Their numbers from the beginning were never very high which gave them the nature of transient beings. This violent campaign against them proved that their time has ended. And despite being known for immortality and agelessness, they are still vulnerable to the curse of death, especially when their weaknesses are exploited. Through this, the Tokugawa further the idea that they are not gods for they bleed like humans, they are nothing more but abominations. The hunts intensified through the span of thirty years, their numbers plummeted dangerously. Others of their kind who seek to continue their lineage had allowed themselves to create taboo children with the humans who offered affection and mercy instead of disdain and outright hatred towards them. There was even a small hope that these children of two worlds would serve as a bridge for coexistence and harmony of past and future.
These are the Hanyō - offspring of a yōkai and a human parent, Unlike their full-blooded predecessors, they are more human in physiology, they may inherit certain features of their yōkai parent like a tail, ears, and so forth, but never all. Their aging process are more similar to yōkai, but their lifespan are shorter, though inevitably longer than that of a human. They are also prone to lose their mind to the inherent bestial trait present in all yōkai, which made them unpredictable and a danger. Their strength and abilities are weaker than those of their yōkai parent, but they are stronger still than humans. Though, the weaknesses of their yōkai parent is either non-existent or halved, making them stronger in that aspect. This was viewed as more treacherous than the existence of yōkai by the Tokugawa as this was a clear betrayal to the human kind. That is why they are hunted more ferociously to the point of obscurity and death, for they were heresies.
There was no doubt the hunts did their purpose. These fabled creatures are nothing more than a myth, so they officially say. Still there are those who cling to life stubbornly, they existed by assimilating themselves to the current human society. Hiding their features, living in the shadows, isolating themselves, limiting their mythical abilities as not to rouse suspicion which would most certainly lead to their extinction.
Of course, this would lead to quite a round of rumors for those who are not careful or simply had enough with the principle of living in fear. One very popular is the whispers about yōkai openly working with the Yakuza...
But half of what everyone knows about that gang is covered in a fog of blurry facts and crafted lies. In short, they are stories created to strike panic and fear to bad children. That is what is officially said.
However, we do know that somewhere in between, there is the absolute truth.