It has been a millennium since the dawn of the war between the aradama and the Toji and there are absolutely no signs of the conflict ending.

This status quo had more or less remained the same throughout the centuries; the aradama had failed to destroy humanity while the Toji had failed to eradicate the aradama. However, this would all change during the 123rd National Swordsmanship Tournament. One after the other, multiple calamitous events rocked the island nation of Japan to its core...