The era of demons has arrived, as predicted by Dr Faust. Regrettably, Faust is approaching death and cannot personally confront this looming peril. Instead, Faust assigns the duty of banishing this fresh evil presence from the planet to a young boy named Shingo Yamada. Faust discovers a marking on Shingo's forehead that indicates he is the chosen warrior against demons. Faust summons Mephisto, a devil who appears to lack enthusiasm, from hell, which could be the Earth's only hope for survival. Shingo and Mephisto sign a blood pact to safeguard humanity, and together they embark on a mission to defeat the supernatural realm.