Kishin Dōji Zenki FX: Vajra Fight is based on the manga Kishin Dōji Zenki by Kikuhide Tani. Once upon a time the Japanese priest Enno has fought and defeated the demon lord Zenki. Zenki was sealed for centuries in the magical bracelet that the Enno family carried through generations. But now, in modern-day Japan, demons called Seeds of Karuma, who worship an ancient evil goddess, began to appear on the Earth, bringing death and destruction. Enno's descendant, a lovely young girl named Chiaki, has no choice but to use her bracelet to summon Zenki! But while being sealed, Zenki has reverted to the form of a nasty, greedy little boy. Chiaki must evoke the power of bracelet to make Zenki fight on her side, and destroy the demons!