As part of his training to become an Exorcist, Rin gets himself enrolled at the True Cross Academy. On his first day of classes, Rin becomes shocked to know that his twin brother Yukio is already an Exorcist and will be one of his teachers.

Shiemi manages to calm down Rin, who is captured by Arthur Auguste Angel, the current paladin, and taken to the True Cross Order Headquarters in the Vatican along Shura and Mephisto Pheles. Meanwhile, Rin's classmates become astonished when Yukio reveals to them that he and his brother are sons of Satan, but offer their help regardless, and they set for Kyoto looking for the descendant of the swordsmith who forged the Demon-Slaying Blade to have it fixed. Before the Order's upper echelons, Mephisto states that his reason for keeping Rin alive is to have him confront Satan, and just when he is trying to convince them to agree to his plan, an enraged Amaimon breaks in, eager to confront Rin once more.