Since its founding, Tougenkyou has been a place where humans and youkai coexist peacefully. However, after a taboo is broken in an attempt to resurrect the villainous youkai Gyuumaou, the "Minus Wave" spreads across the land. As this ghastly force runs rampant, youkai begin to lose their self-awareness, leading them to devour the townspeople. Tasked by the Three Aspects—the messengers of the heavens—to halt Gyuumaou's resurrection and restore peace, Sanzou Genjou gathers three former comrades, none of whom fit the definition of ordinary. Being half-human, Gokuu Son, Hakkai Cho, and Gojou Sha are the only youkai possessing the power and spirituality to withstand the Minus Wave. Despite his skepticism about trusting them due to their mixed heritage, Sanzou heads west with his companions to eradicate the growing threat.