Once there was a military power called “Amamikado” which invaded other countries and expanded its domain. There were two princes in Amamikado. The younger prince was named Oguna. His father, the Emperor of Amamikado, trained him as an assassin. Oguna was hungry for power to help his father. This is a tale of an assassin before he meets Izumo.

Three men named Takeru converge in the Oyashima islands, looking for the legendary Sword of Susanoh. After an unexpected chain of events the three – Izumo no Takeru, Kumaso no Takeru, and Oguna no Takeru – decide to band together in hunt for the famed weapon, though each has his own reason for doing so. Their first stop is the female kingdom of Jagara, where their destiny awaits…