In a realm of magic and warfare, the Kingdom of Nor, part of a coalition battling the Demon Lord, endeavors to vanquish their foe by summoning a hero from a distant world using a clandestine incantation. However, the enigmatic hero who materializes is none other than Kagei Soji, a soulless serial-killer. Unbound by rationale, Soji, bearing the moniker of a hero, capriciously decides to execute the princess and her escort as the sun shines brightly overhead, swiftly fleeing the royal abode. His merciless actions dictated by a twisted meteorological criteria – slaughter under the sun's rays, spare under clouds. Amidst the verdant woods, Soji crosses paths with Mythos, a downtrodden slave girl, who extends a helping hand, intertwining their fates. Their companionship, though serene, remains fleeting, shadowed by the relentless pursuit of a formidable adversary named 'Mixing,' tasked with hunting down and eliminating the rebellious 'hero.' Embrace the defiance against preordained destiny in this unconventional tale of dark fantasy!