Summary i got from animenewsnetwork:
Allen Walker is a young Exorcist who has a cursed eye that can see the suffering of the Akumas created by The Millenium Earl. He travels to England to the Headquarters of the Exorcists where his Master has sent him to meet with the other Exorcists. The battle with the Millenium Earl and the Noah Family vs. the Exorcists intensifies when some of the best Exorcists begin to get killed by hoards of Akuma. Japan takes center stage in this end of 19th Century plot in order to not let the entire human race be turned into Akumas and the Exorcists have the power of "Innocence" that was given to them by God on their side.

We can also RPG D-gray man...
Talking about other stuff since this is also an organization as well
like love problems....or school...