Blue Exorcist, Vol. 12 (Paperback)

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.
As the True Cross Academy festival reaches its peak, trouble is brewing. While Izumo confronts Nemu Takara, Rin and the rest of the Exwires race to find her. The betrayal they discover and the tragic details of Izumo's past will shake them to the core and herald the beginning of an all-out war between the Illuminati and the Knights of the True Cross