Description: The worlds of humans and demons have overlapped since time immemorial, and a young woman named Yuri and her servant, Karas, have long maintained order and balance between the worlds. But humans have finally lost their fears of the denizens of darkness. Disgusted by human arrogance, Karas turns his back on the laws he helped uphold for so long, taking the name Eku and leading a group of mechanized demons in an attack against the human race.