Ataraxia Reject

Yamazaki Shiro lives in a world where the few people who gain the powers of creatures called Ash Wraiths train to become Rooks: Warriors who specialize in defending the world from the Ash Wraiths. But, Shiro is unique in more ways than one. Shiro is the only male Rook, and the only male known to have the abilities of an Ash Wraith. The rest are female. While most Rooks only get a portion of an Ash Wraith's power, Shiro received an Ash Wraith's full power, which makes him the only Rook to use the "Dark" of an Ash Wraith. This is kept a classified secret, until he gets a call from childhood friend Natsumi who tells him to enroll in Ataraxia, a school for Rooks. Against his will, Shiro makes his debut at Ataraxia as the first and only male Rook, but his presence is not well received by all female student body.