The ExWire members at True Cross Academy were shaken up after discovering that Rin Okumura, one of their own, is the son of Satan. But, their attention turns to a more pressing matter when the left eye of the Impure King, a mighty demon, gets stolen from the academy's Deep Keep. To uncover the identity and plot of the thief, Rin and his fellow ExWires travel to Kyoto when an attempt is made on the right eye. While they work together on the task at hand, Rin feels disconnected from the other exorcists. He undergoes specialized training to control his dark power, hoping to reconcile with them. However, when the right eye gets stolen again, he realizes a traitor might be among them, putting everyone in danger and requiring maximum power.