In the fictional Warring States Period, Japan has been ruled by unknown life forms "ghosts" for 150 years. Only the "Samurai Group" resisted their rule and has been fighting tirelessly. Musashi and Kojiro also yearned for samurai and vowed to form the strongest samurai group one day. However, the town where they live regards ghosts as gods and samurai as heretics. Musashi can only hide his dream in his heart until one day, he encounters a scene where a human is brutally killed by a ghost. In order to regain the oath with Kojiro, Musashi challenged the powerful ghost...!