If you're reading a review of this book, you're looking for an opinion on which to base your purchase. Here is mine, but I also discern it from the facts. I highly value this book more than any other I own on Ninjitsu. I have learned an enormous amount from it, and it has improved my life. Some people say Ashida Kim teaches only basic karate moves. Ashida Kim teaches invisibility here and stresses it more than anything. The prime concern with all the tactics are hiding oneself to stop or avoid a conflict. There may at some points be moves that resemble karate but, there are only so many ways the body can move. All styles of physical combat are merely variations.
As for Ashida Kim being a fake, A Zen Koan fondly comes to mind (there are a few versions of it): A decorated martial artist comes to a new teacher to learn a new style of combat and is invited in for tea. He talks about all of his victories as the sage pours the hot liquid... when the cup is full, the sage keeps pouring, spilling it on the hand of the student. "WHY DID YOU KEEP POURING???", asked the student. "Your head is like the cup", said the sage.
The point is, Ashida Kim has something to teach. Call it what you will. He isn't here to prove a point, himself, or his style. What you can learn from something and how it affects your life is what counts. There are many roads up the mountain who's summit is your goal. This may be the road for you, maybe it isn't. Life is a learning process.
For anyone who believes that Ashida Kim is a fake I tell you that his writings and wisdom are not to be confused with a common fraud's. This book has excellent techniques, guidelines for life, and pictures. It is a book that is so profoundly written that it has to be reviewed several times by an average person to understand its meaningful context. This is the first book I purchased from Ashida Kim, and it has encouraged me to purchase others. Then, about the demon masks and strange movements to the unbelievers, they might be from somewhat slightly different styles, and about how he mentions everything in Chinese culture, maybe he studied it or something! But I still believe this is an EXCELLENT book by an EXCELLENT offer. Read it!