Glenn Morris' book is way out there. This is not a book about a "Ninja Master" but a hobbyist (his words) of Ninpo. If you are into kundalini, asteral planes and learning how to see peoples' auras (which he taught several people to do in 10 minutes) buy this book. If you want to learn about Ninpo, read books written by the current Soke, Masaaki Hatsumi or if you can find them, books by Shoto Tanemura.