Keine Kamishirasawa is a were-hakutaku who acts as the Schoolteacher And guardian of the Human Village. 
As a proper teacher, she doesn't like people who are discourteous, but other than that, she is generally friendly towards humans except, for when she has assumed her hakutaku form At Full Moon.
she can "eat" history. Though it is stated as "eating", it is clear that she is only concealing history from outside viewers. In her hakutaku form, She Can Create History And Know All History. Touhou