Rin and his exorcist classmates are caught in a secret war against the forces of darkness. Raised by Father Fujimoto, a famous exorcist, Rin Okumura never knew his real father. One day a fateful argument with Father Fujimoto forces Rin to face a terrible truth - the blood of the demon lord Satan runs in Rin´s veins! Rin swears to defeat Satan, but doing that means entering the mysterious True Cross Academy and becoming an exorcist himself. The tragic story of what happened to Rin and Yukio´s mother, Yuri Egin, continues to unfold. Yuri and Father Fujimoto were once up-and-coming young Exorcists involved in Section 13´s extensive operation to research elixirs of immortality and develop clones to house the spirits of demons. The project seemed to be moving ahead until the unexpected manifestation of a demonic spirt into one of the clone bodies. And not just any demon-the most powerful demon of all: Satan!