Is there a case in Japanese mythology of an Oni (Big Ogre from a desolate place) willingly helping people or being a inhabitant of a village? If not why can they not integrate into human society? What forces them to live far from civilization?
TL;DR Japanese ogres - Why can't they just be like normal people?
According to "Shugendō" , their founder "En no Gyōja" has two Oni （前鬼・後鬼） as Shikigami and they follow En no Gyōja after being converted by him.
But very often, Oni do not help people. This is due to the origin of Oni.
The origin of Oni varies, for example, the historian 高橋昌明 suggested that the famous 酒呑童子 is related to the smallpox outbreak at that time. This is why the Oni does not help people, because it is used as an explanation of why there is a smallpox outbreak.
Some also suggested that Oni symbolizes the locals that fought against the central government at that time.
