Are Ninjas Real: The True History Of Ninjas
If you are interested in ninja training you must know that historian Kiyoshi Watatani states that the ninja were trained to be particularly secretive about their actions and existence.
If you are interested in ninja oufits and in the history of ninjas, watch this awesome documentary.
A final but detailed record of famous ninjas employed in open warfare occurred during the Shimabara Rebellion (1637–1638). A diary kept by a member of the Matsudaira clan, the Amakusa Gunki, reported many ninja names.