Why are demons considered good and bad in Japanese culture?

Answer 1

Japanese culture typically associates particular animal species with demons, with some of them being good, some tricksters who are selfish, and others bad. For example, foxes (and therefore "fox demons") were typically considered clever creatures that only wanted to test and trick humans, but they were not "evil."

Japanese mythology is rife with supernatural encounters involving talking animals and other non-human creatures, and in these stories, there is typically a lesson to be a learned (a moral). Popular stories often resulted in a common association being formed about that animal, e.g. crows are considered messengers of the gods (positive association) or are meddlesome, selfish, and unholy (negative association, typical in stories featuring tengu, a mythological half-man half-crow).