everything is hear say unless you were there. even legal documents can be falsified. Asking for proof is like knowing who killed JFK, is there life out there, am I really alive. I come the conclusions through my own state consciousness. Look at the stories and come to your own conclusion because to be honest unless you where there with a video camera and witnesses is hard to prove to anyone. I know simply what I’ve read in The Way of the samurai and heard from elder instructors and people, so sorry no concrete proof kinda like religion man find your own self proof. (ow and it’s hard to present legal documents for a civilization that existed centuries upon centuries ago in asia)
Ow and one more thing provide “legal documentation” (as you put it) that ninja’s came from an actual practice of self defense and I’ll hush.