A cursed teenage boy saves mankind one soul at a time. 
Set in a fictional 19th century England, D.Gray-man is the story of Allen Walker, a 15-year-old boy who roams the earth in search of Innocence. Washed away to unknown parts of the world after The Great Flood, Innocence is the mysterious substance used to create weapons that obliterate demons known as akuma. 
Allen Walker continues the tale of his past as an orphan child working in a circus. He was called Redarm then and knew little but misery in that life. He did, however, befriend one of the clowns, Campbell, and his dog, Allen. Another clown, Cosmo, hated both Campbell and Redarm and performed a dispicable act in order to torment them. Meanwhile, Allen's future master, Cross Marion, was finally reaching the end of a long hunt for a most elusive quarry.