A mysterious giant demon appeared in modern Japan. The protagonist "Hibiki" transformed into "Kamen Rider Hibiki" and started a battle with the demon. Unexpectedly, Hibiki was defeated and seriously injured... In order to find out the original form of the demon, Asumu and Sejiro began to look up ancient materials. Asumu suddenly discovered this Warring States period document, which actually had the same name as her... A legend of fierce fighting between ancient and modern times begins! This work uses modern plots to bring out the disputes between the ancient ghost clan and the demon, and indirectly brings out the reason for the establishment of the "Warriors" organization.