Ga-Rei

The Enchained Spiritual Beast Ga-Rei (喰霊, Ga-rei), also simply known as Ga-rei, is a manga series written by Hajime Segawa. It has been serialized by Kadokawa Shoten in the Shōnen Ace magazine and collected in twelve tankōbon volumes as of January 26, 2010. A prequel anime adaptation, Ga-Rei: Zero, aired from October 5, 2008 to December 21, 2008 which details the backstory of the main heroines, Kagura and Yomi.

Plot
Freshmen high school student, Kensuke Nimura has the ability to see ghosts. His life changes when he meets Kagura Tsuchimiya, a girl with the power to summon a "Ga-Rei" called Byakuei. The two work together to find evil spirits and devour them with the Ga-Rei under the auspice of the Ministry of the Environment's Supernatural Countermeasure Division.