The story is set in medieval Japan, most likely during the Edo period between the 17th and 19th centuries. The rulers of Edo have learned of a powerful Dragon God sealed away long ago — a being whose defeat was said to have made the founding of Japan possible — and they intend to harness that power for themselves. A young warrior named Gento and his feline companion Benimaru arrive at a northern village and are immediately attacked by Edo soldiers. Determined to understand why, the two embark on a journey that takes them across the whole of Japan.