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. After a fierce battle, Satan has become part of the earth, transforming the land around him into his realm. His heart now lies at the center of this cursed area, protected by an impossible fortress. The last remaining shard of the crystal of Shemihaza is now the only hope of defeating Satan, and Shiemi--the Saio and daughter of Shemihaza--must bear it to him! Reunited at last, all of the Exwires must now face their fears and prepare for the final assault on Satan's stronghold. For Rin, it will also mean coming to terms with his demonic heritage, and what price he will have to pay to truly defeat his unholy father...