Ga-Rei

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

Plot
Freshman Nimura Kensuke has the ability to see ghosts, and his life changes when he meets Kagura, 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.