Ga-Rei Zero

Plot Overview

The Japanese Ministry of Defense has an anti-paranormal special forces group called the Paranormal Disaster Countermeasure Headquarters (PDCH). They are the ones responsible for protecting Japan and its people from supernatural events and monsters. However, things don't go so well on one of their missions, which leads to intervention by the Ministry of Environment's Supernatural Disaster Countermeasures Division (SDCD) after the PDCH had sustained large numbers of casualties battling demons.
 
The SDCD is a small group of individuals who have special abilities to fight supernatural monsters. There are a few exorcist families that belong to the SDCD. Yomi and Kagura, two daughters of two of the more prominent exorcist family, are both exorcists as parts of the SDCD. They both train with special swords and a companion spirit that has been passed down for generations. 
 
At the beginning of the series we see Yomi going on a murderous rampage throughout the city along with other supernatural monsters. Kagura tries to confront Yomi herself, and hopefully talk some sense into her. Yomi does not seem to be listening and keeps telling Kagura to kill her.
 
Much of the series then retells the story of both Yomi and Kagura and the other members of the SDCD. How Yomi became what she is now and how Kagura and Yomi became very close friends. The series also shows the important role of exorcists like Yomi and Kagura in fighting the mysterious supernatural monsters that show up every now and then. There is also some drama between the exorcist families, and the power of the Sesshoseki stones. 
 
A Sesshoseki stone, although it gives the user great regenerative abilities and slows aging, is also inherently evil because it was made from the Nine-Tailed Fox's spiritual power. Thus the user has a high risk of succumbing to its evil power.