The ninja manuals list a number of advice and techniques, many of which are of questionable origin. It is believed that these manuals were written by a number of different authors over a period of time, and as such, they may not be accurate. In addition, the manuals claim to provide instructions on how to perform assassination and espionage, which are highly questionable activities. As such, the origin of these manuals is suspicious, and the information contained within them should not be trusted.
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