150 years ago, the people of Hinomoto City were freed from samurai rule and lived peacefully, worshipping the mysterious demon who freed them as a god. Destined to mine the stones that would become the demon's prey, Musashi learned the harsh truth: humanity was enslaved by beings from another dimension, and the samurai were the last bastion fighting for freedom. Hiding his true feelings from his comrades and estranged from his childhood friend Kanemaki Kojiro, Musashi lived in fear until graduation day. When the graduates arrived at the mine, they were terrified by the inhumane treatment of the miners and the bizarre behavior of their supervisors. However, with Kojiro's help, Musashi managed to persevere. While the demon leader caused chaos in the quarry, Musashi was once again saved from death by the samurai of the Takeda clan. Having recovered from his humiliation and with a yearning for adventure in his heart, Musashi embarks on a journey to become a samurai and establish his own clan!