Once there was a legend of a sword. It is said that the sword of a rune god was sealed up in "Jagara-Mogara". When the spirits of Light, Water, and Earth come together, the seal will break, then the sword will be immortalised. That is the sword of Susanoh.
Izumo, Kumaso, and Oguna, upon pursuing the sword of Susanoh, came to the nation of Jagara ruled by an Empress and her army of women. They got involved in the wars between Jagara and Amamikado, but what awaits them isn't the clash between two nations, but the darkness involved with the sword of Susanoh that everyone is seeking.