In the 13th century, on the island of Konoshima there existed two feudal clans, the Kagami and the Sue, both aligned to the same Daimy?. They lived in peace until war on mainland Japan crushed the Daimy?. The Kagami swore fealty to the new Daimy? 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. (Wiki)