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.

Exhausted by the effort to contain Satan, Shemihaza has transferred her role--to Shiemi! Rin and the other Exwires are stunned to see Shiemi again, and old friends reunite. But although the ritual to seal Satan was completed, the demon lord transformed in order to survive. Now, his immense form is part of the earth itself, with his heart protected in the center of a vast fortress! The Exorcists and Exwires of the Knights of the True Cross regroup and ready themselves for a renewed assault on Satan's stronghold, but this time, the forces of the Illuminati will also be defending their father...