Kannazuki no Miko

The highborn Himemiya Chikane is cool and aloof, the perfect young lady of good breeding. Kurusegawa Himeko is devoted to her, and secretly her friend. Their lives are undisturbed in their school, until an ancient evil suddenly rears its head. To combat it, Chikane and Himeko must take on the roles of shrine maidens of the Moon and Sun.