In an era where Japan is under the control of demons, two warriors fight to overthrow their rule.

Freed from the rule of samurai 150 years ago, the people of Hinomoto live peaceful lives and revere their liberators-demons whose true forms remain elusive-as gods. Fated to mine rocks for the demons to feast on, Musashi knows the grim truth: humanity is enslaved by these otherworldly beings and the samurai are the last bastion fighting for freedom. Hiding his true opinion from his peers and growing distant from his childhood friend Kojirou Kanemaki, Musashi lives in angst until the day of his graduation. When the fresh graduates arrive at the mine, they are horrified to see the inhumane treatment of miners and the uncanny physical appearance of their overseers. However, Musashi manages to endure thanks to Kojirou's help. As the demon leader wreaks havoc on the quarry, Musashi is saved once more from certain death by the Takeda samurai clan. Recovering from humiliation and yearning for adventure, Musashi embarks on a journey to become a samurai and form his own clan.—MAL Rewrite

During the Warring States era, the feuding generals were suddenly struck down one after another by the demonic Kishin. In the 150 years since, groups of individuals have continued to resist Kishin control. They are called Bushi bands. When they were young, Musashi and Kojiro would hear tales about the Bushi from Kojiro's father, and the two of them dream to form the strongest Bushi band. One day, as Musashi struggles with his choices, he witnesses humans being torn apart by oni. Forced to face the truth, Musashi rises up against the powerful oni to make his dream with Kojiro come true!.—Crunchyroll