The story is set in the year of Meiji 64, when Tokugawa Yoshinobu held power in another Japan. The country relied on the energy source "Dragon Vein" to form a unique development that mixed Edo and science. But behind the prosperity, the anti-establishment organization "Snake" is brewing the fire of revolution. The Tokugawa government commissioned the dark organization "Nue" to expel it. The heroine, Yukimura Shoha, was killed when she was young, so she became the executioner of "Nue" and continued to look for Snake Nome for revenge...