The Ariake Seal (有明結界陣 Ariake Kekkai; Ariake Barrier Formation) is a barrier created by Kagari Ubusuna under direct orders from the Japanese government in order to seal Akujiki away and prevent the Hellspawn from returning.
Formation of a SealEdit
After Hiruko's defeat and the destruction of the Golden Palace, Hotsuma died with the intent of taking Akujiki down with him. The government searched for him, but found only the sword Akujiki, shattered.
Since ancient times the sword had brought great calamity. Said to grant it's wielder immense power, the sword's curse had claimed the lives and souls of countless men. For decades the Oboro fought valiantly to end its bloodstained legacy. To insure that Akujiki may never bring forth calamity again, and prevent the return of the Hellspawn due to Hiruko's lingering dark energies, the Japanese government orders Kagari Ubusuna of the Ubusuna clan to seal the demon sword away.
Using the teachings of the Ubusuna's Onmyoji, the young priestess performs a ritual to seal Akujiki by scattering its shards throughout the Tokyo. Using sacred jade mirrors powered by Yang energy, the blessings counter the Yin energies of Akujiki that connect the portal to the Hellspawn realm, and keep the gates of the evil realm sealed.
However, the Nakatomi family desired Akujiki, and in their greed, sent their forces to break the seal and steal an Akujiki shard from the Ariake fortification, resulting in the return of the Golden Palace and the Akujiki shards raging out of control, creating newer, deadlier Hellspawn.