Tamayorihime. A priestess who held immense spiritual power. For centuries, her descendants have guarded the demon sword Onikirimaru, keeping it under powerful seals and a watchful eye. After decades of extensive research, a group of scientists calling themselves "Tenyakuryou" finally perfected two things: a vault that strengthened the seals, and the isolation of the essences that gave the six guardian families their power.But they were missing an essential element in keeping