Ao no Exorcist: Kyoto Fujouou Hen  

Blue Exorcist: Kyoto Saga, 青の祓魔師 京都不浄王篇, 青之驱魔师 京都不净王篇, Blue Exorcist: Kyoto Impure King Arc, Ao no Exorcist: Kyoto Fujouou-hen, Blue Exorcist Season 2, Blue Exorcist 2

The members of True Cross Academy's ExWire group are feeling overwhelmed and scared after learning that one of their own classmates, Rin Okumura, is actually Satan's son. Although they have more pressing issues to deal with at the moment, such as the theft of the Impure King's left eye from the academy's Deep Keep, they are sent on a mission to investigate the mystery behind the thief and their ultimate goal. Despite initially working together, Rin feels increasingly isolated from his fellow exorcists due to his struggle with reconciling with them. To address this, he undergoes specialized training to control his dark power. However, when the right eye of the Impure King is stolen not long after they arrive, the group faces an unthinkable threat: a traitor amongst them.

The adaptation starts at volume 5 and ends at volume 9, chapter 34 of the manga.