Nikurashi are a type of ugly humanoid yokai closely linked to the Jumen, like them the Nikurashi have very little history in terms of lore outside being depicted in certain art, where they are always depicted as woman dressed in sensual clothing who have supernaturally hideous faces.
While frightening in nature they share the same status as the Jumen in being fairly neutral, even if Nikurashi do have a more sinister side as their name is a play on "hateful".