Source taken from Wikipedia.org
D.Gray-man is an ongoing Japanese manga series written and illustrated by Katsura Hoshino. The series tells the story of a boy named Allen Walker, a member of an organization of Exorcists who makes use of an ancient substance called Innocence to combat the Millennium Earl and his demonic army of akuma.
D.Gray-man follows the adventures of 15-year-old Allen Walker, whose left arm can transform into a monstrous claw and destroy akuma, evolving machines created by the Millennium Earl to help him destroy humanity. As ordered by his master General Cross Marian, Allen becomes an Exorcist, people who can destroy akuma, for the Black Order, an organization attempting to stop the Earl. He becomes a powerful asset for the Order because he can detect disguised akuma with his left eye. Allen is sent to recover pieces of Innocence, a substance that gives certain people, called Exorcists, the ability to destroy akuma.
