Written by Tsuneyoshi Matsuno this book is filled with rare and ancient knowledge and history opf the Ninja plus a complete section on Kiai Jitsu. Plus studying a person's face to see their true nature and thinkings. He also discusses the inner secrets of the "Black Art" more commonly known as black majic. This is not a technique book but a delve into the secret side of Ninjutsu dating all the way back to the 1500's.