After Musashi frees Michiru Saruwatari from a demon, Kojirou Kanemaki discovers his father was part of the Uesugi clan. Determined to learn his roots, Kojirou and his Kanemaki allies join Uesugi"s campaign against Awaji Island"s demon lord, Yamata no Orochi—a colossal eight‑headed dragon threatening the region.
When Musashi joins Uesugi"s coalition, he confronts the reality of fighting formidable demons. Undeterred by his own powerlessness and difficulty in teamwork, he must master cooperation with new comrades.
Meanwhile, the Obsidian Eight—a faction hunting the Obsidian Goddess inside Musashi—re‑ignites its pursuit and plots to derail the island assault.
Their efforts are complicated by rival mercenaries seeking the Obsidian Goddess for gain.
The mission demands martial prowess and strategic insight, as each dragon head embodies a different elemental force.
With escalating chaos, Musashi and his friends must thwart the schemes of multiple factions vying to seize the Obsidian Goddess.
