This was the first small press Bujinkan book ever authorized by Hatsumi-soke. Translated by an amazing team of budoka lead by Joe Maurantonio, shidoshi. You can buy it by clicking on the book below:

The Shadow Warrior highlights Darryl Caldwell's insight on the early years of ninja art and culture in America. Surviving the bruises, flashing blades, and dizzying mental shifts, he emerged as one of the first black belt teachers outside of Japan.