Yukio sets out to the school's Exorcist-only shop to stock on some supplies along with Rin. There they find that the owner's daughter, Shiemi Moriyama, is being afflicted by a demon that dwells in her family's garden and, to save her life, they confront it by themselves.

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.

Rin and Yukio find that their friends from the monastery where they were raised where attacked by a masked individual who covered their entire bodies with an seemingly indestructible spider web. While pursuing the culprit, whose objective is to attack anyone related to the son of Satan to make him suffer, Yukio stumbles into Neuhaus who flees without further explanation. Despite having his sword sealed by the web, Rin insists to go after the masked one but is held back by Yukio and Shura, until he gets word that his Suguro, Renzo and Konekomaru are being attacked too and rushes to help them. By managing to control his flames properly, Rin defeats the attacker, who flees thanks to Neuhaus who reveals her to be his wife, and safely releases his friends.