In the 13th century, on the island of Konoshima (in the Seto Naikai, Inland Sea of Japan) there existed two feudal clans, the Kagami and the Sue, both aligned to the same Daimyō. They lived in peace until war on mainland Japan crushed the Daimyō. The Kagami swore fealty to the new Daimyō while the Sue were loyal to their master until the end. The conflict between the two began with the Kagami drawing the Sue off of the island and into battle. The Sue, having been defeated in battle, then lost their sacred sword the Yugiri. For centuries after, secretive battles were fought that were fierce, but not widespread.