As the ferocious battle of Awaji Island unfolds, Hinomoto is now under the rule of oni, led by the formidable Kishin. Musashi and Kanemaki Kojiro, determined to assemble the mightiest Bushi group, embark on a journey that leads them to form the Kanemaki Bushi with Hattori Tsugumi. Armed with the legendary Kitetsu Blades capable of defeating oni, they take their first significant step towards their ambition. In Harima, they confront Uesugi Tatsuomi and the Uesugui Bushi, uniting to vanquish the colossal oni threat, Yamata no Orochi, the Artillery Wyrm. Alongside allies like Takeda Naotora, Shimazu Akihiro, and Amako Katsumi, as well as the reserved princess Saruwatari Michiru, Musashi and his comrades engage in the perilous hunt for the invincible demon god. The stage is set for the ultimate showdown against a seemingly indestructible foe, marking the beginning of their most daunting battle yet.