Mukaino Miki

Miki is the classmate and childhood friend of the protagonist, Masaki.
Despite looking like a normal girl from outside appearance, Miki possesses a supernatural power that allows her to communicate with an omnipotent existence. It grants her access to all information from the past, present and future, with a price to pay. Every time Miki uses the power she would get a headache, and the harder to retrieve that information, the more intense the headache becomes.

Spoiler

Later on in the story, Miki had an accident and was possessed by Sharo - a fox youkai. Because of that, she found herself being hunted down by demons who want his soul. With Sharo's assistance, Miki has to fight those demons in order to keep both Sharo and herself safe.

A kind and obedient girl, she worries a lot about Masaki's sloppiness in his daily life.