Shu is always in trouble with money but manages to live thanks to the support given by his ex-girlfriend Ayano and the ever-devoted Kisara. The same goes for his job as a PMC. With Ayano's cooperation, Shu won a bidding war at a discounted price to participate in the "D Hazard" prevention operation that occurred in a casino. At the scene of the demon extermination, he planned to rely on Kisara's demonic powers, but she is nowhere to be found due to the money situation ruining her mood. As a last resort, he works with Ayano's leading, major PMC and confronts the Demon, but bit by bit, the battle becomes something suspicious...

Although the Demon Possession that caused the large-scale power outage was exterminated, the problem remains unresolved as the power shortage in Bayron City continues. Meanwhile, Kisara witnesses a secret meeting between Ayano and a mysterious man. To confirm Shu's feelings, she uploads a photo of the scene to social media. Successfully lured by Kisara, Shu rushes Ayano and the mysterious man – an Anti-Demon Bureau detective named Tetsuya Mikami – and, in an unexpected flow of events, realizes that Ayano was hiding her intentions and planning behind his back. An unparalleled sense of tension lofted between the two.

The Celestial Abbey — — Publicly seen as advocates for philanthropy, they are the world's largest Exorcist group. The identity of the mysterious nun who suddenly appeared in Bayron City is one of the most dangerous persons in the Celestial Abbey, Sharon Holygrail. Known as "Sharon the Chaste," she is one of the 12 remarkable Exorcists called "Living Relic." The Anti-Demon Bureau faces a growing sense of danger with the emergence of a new power that could shake the framework of their organization. Meanwhile, as Shu is injured and sleeping, Kisara tells Ayano about the events atop the snowy mountain that led to the intertwined fate of her, Shu and Sharon.

In the middle of the battle against the demons on the artificial island, Kisara was stabbed by a spear before Shu's eyes. Saved by Ayano and Sharon, Shu helplessly evacuates from the fight when he sees the person he's been looking for—his younger sister, Kanna. Then, humanity's desperate resistance, backed by the focused efforts of Bayron City, proves futile as the extent of the large-scale disasters caused by Kanna, now certified as an S-Class demon, expand. Kisara collapsed due to her injuries and lost consciousness as her vitals disappeared. Unable to move, Shu just stares at her. And as if responding to his heart, Kisara gently awakens.

Shu is always in trouble with money but manages to live thanks to the support given by his ex-girlfriend Ayano and the ever-devoted Kisara. The same goes for his job as a PMC. With Ayano's cooperation, Shu won a bidding war at a discounted price to participate in the "D Hazard" prevention operation that occurred in a casino. At the scene of the demon extermination, he planned to rely on Kisara's demonic powers, but she is nowhere to be found due to the money situation ruining her mood. As a last resort, he works with Ayano's leading, major PMC and confronts the Demon, but bit by bit, the battle becomes something suspicious...