D.Gray-man (ディー・グレイマン Dī Gureiman) is a manga series by Katsura Hoshino. The anime version began airing on October 3, 2006 and it is scheduled to span in 52 episodes.

The plot revolves around Allen Walker, an Exorcist, in the end of the 19th century Europe. Allen is a member of the Black Order, a group of Exorcists connected with the Vatican. Their mission is to stop The Millennium Earl, an evil ghoul intending to cleanse the world by destroying all the humans in the manner of Noah's great flood.

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.

From Wikipedia / Anime News Network