Having Shiemi as a new classmate, Rin's total disregard for classes brings forth the anger of another classmate of his, Ryuji Suguro, aka "Bon". After learning of Bon's story, Rin finds that they have more in common than he would like to admit.

Rin and his classmates succeed at the task gave to them by their teachers, but the camp is attacked by Amaimon, who holds Shiemi hostage to force Rin to fight. Having no option but to go full force against Amaimon, Rin is forced to reveal his secret by exposing his true form in front of his friends. With the other Exwires fleeing astonished after learning the truth about him, Rin easily overpowers Amaimon, but loses control of his flames and goes on a rampage. The Demon-Slaying Blade is cracked in the process.

Rin and his companions manage to flee from Satan who starts destroying the True Cross Academy with his flames. Knowing that Satan still stands beside the Gate because Rin has the power to destroy it, Shura comes up with a plan to distract him to give Rin an opening to do it, while the other students help evacuate the school. Their plan fails when Shiemi intervenes trying to dissuade Yukio with no success, but Rin manages to have his brother regain conscience and expel Satan from his body. However, the gate keeps getting stronger and it will not be long for Gehenna and Assiah to merge into one single realm.