Over 500 years have passed since a mortal named Bryce Boltzmann endured a life-altering tragedy at the hands of Astaroth, the Demon King. His wife murdered, left defeated and rendered immortal, he now moves through life without aspirations other than finding his next drink. Alongside the clandestine group, National Anti-Demon Agency, he pursues redemption through the extermination of demonic forces along with his agency partner, Arcadia.