In the mystical setting of ancient Japan's Heian Period, where malevolent spirits lurk in the shadows of nature, a courageous girl, disguised as a man, embarks on a perilous mission with her beloved companion. Known as 'Kaidomaru' and bearing the fiery emblem of 'Flame' on her arm, she stands as one of the revered 'Four Devas'. Kaidomaru valiantly fights in memory of her lost love, Raikou Minamotono, who bravely gave his life to safeguard Kyoto from a vengeful princess tainted by a malevolent ogre's curse. The very princess she once shared innocent moments with now stands as her greatest adversary, testing her loyalty and resolve.