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, now joined by two companions, is still on the run and trying to deal with his demonic alter ego, the Fourteenth. This means avoiding erstwhile allies as well as overt enemies. He also has to prevent one of his companions, fellow Exorcist Kanda, from trying to destroy the Fourteenth while keeping the Fourteenth from destroying his other companion, Johnny, whose zealous devotion to Allen is gratifying but not much help in a fight!