Instruct: Classify the given Amazon review into positive or negative sentiment.
Query: A word of caution.

While Steven K. Hayes likes to make many claims about himself and Ninjutsu, one should be warned that much of what he says about Ninjutsu is simply incorrect. And i dont believe i can stress the this point enough, that is that contrary to his claims in this and his other books he was far from being Hatsumi first foreign student, neither is he or will he ever be the "Foremost Western Instructor". When reading this book one must keep in mind that much of what Hayes says is in conflict with what Hatsumi has taught so just to take it with a grain of salt.