Blue exorcist, vol. 13 (Viz Media)

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 Exwires learn the tragic story of what happened to Izumo's mother, Tamamo, when the Illuminati's mad Professor Gedoin sought her out in order to conduct his insane experiments. Now Izumo has been captured and is next on the Professor's list of test subjects. Rin, Yukio, Shiemi, Suguro and Konekomaru head deep into Dream Town Inari to rescue Izumo, but what they find there is a horror none of them ever expected...