Ancient tales recount the legends of Excalibur, a sacred sword. This blade is wielded by those deemed worthy of its power, granting them extraordinary strength and the title of Arthur. However, a divine miracle leads to the creation of multiple Excaliburs, thereby distorting the fabric of time. Seeking to restore time to its original course, a group of six Arthurs—Danchou, Renkin, Kakka, Yamaneko, Tekken, and Rurou—are sent back to the era when the abnormal Excaliburs first appeared. They are given a single task: to destroy all the Excaliburs of the past, which number one million in total.