The mortal world is now inhabited with Ghouls, creatures who are once humans but died in sorrow and vain. They evolve from time to time yet cannot be seen by normal eyes. Their food source is human, its flesh and soul. This creates fear and terror to all mortals. In order to save them, an institution was founded by the Sacred Seven who were gifted with special powers. Their lineage had grown but only selected ones have acquired their powers called, Ghoulslayers. While the rest of the race and those who can only see through the barrier are called espy. Follow the story of a teenage girl who is part of this world and has missions to accomplish to seek the truth behind the Sacred Seven and her true identity.