The age of demons has begun. Dr. Faust has foreseen this rise of evil. Unfortunately, he is near death and cannot personally battle this upcoming threat. Faust entrusts a young boy, Shingo Yamada, with the responsibility of ridding the Earth of this new evil presence. Faust finds a birthmark on Shingo's forehead that signifies he is the chosen demon fighter. Faust summons from hell what may be humanity's only hope of survival: a less than enthusiastic devil named Mephisto rises. After signing a blood pact to save humankind, Shingo and Mephisto set out to battle the supernatural world.