Towards the end of the 19th century, Allen Walker officially joins the organization of Exorcists that destroy the beings known as Akuma; mechanic weapons made by the Millennium Earl with the suffering souls of the dead. Allen has both a cursed eye and an anti-Akuma weapon as an arm, bearing the power of "Innocence", a gift given to him as an apostle of God. Allen, along with his fellow Exorcists must put a stop to the Millennium Earl's ultimate plot that could lead to the destruction of the world and all who live on it.

Towards the end of the 19th century, Allen Walker officially joins the organization of Exorcists that destroy the beings known as Akuma; mechanic weapons made by the Millennium Earl with the suffering souls of the dead. Allen has both a cursed eye and an anti-Akuma weapon as an arm, bearing the power of "Innocence", a gift given to him as an apostle of God. Allen, along with his fellow Exorcists must put a stop to the Millennium Earl's ultimate plot that could lead to the destruction of the world and all who live on it.