She is the malign deity "Crawling Chaos" Nyarlathotep, or Nyarko for short. Together with "Living Flame" Cthuga, or Kuko, and "The Unspeakable One" Hastur, or Hasuta, they bring you an abysmally terrifying Love(craft) comedy!
The story of Haiyore! Nyaruko-san centers around Nyaruko, a formless Lovecraftian-deity of chaos (Nyarlathotep) who can take on the shape of a seemingly ordinary silver-haired girl. Mahiro Yasaka is a normal high school boy who is being chased by a fearsome black alien one night, until Nyaruko saves him. She explains that the creatures from H. P. Lovecraft's works are actually races of aliens, and that she has been sent to Earth by the Space Defense Agency to protect him…