Real "ninjas" are tied to a school of "non-combative" (ie. stealth) martial arts founded in the late 1300s. Some samurai in the region practiced the art THEMSELVES, which makes it highly unlikely that they despised them enough to make it a policy to hunt them down, throw rocks at them or give them wedgies.
90% of information on "ninjas" in the Western world (including the Wikipedia article "ninja") is 100% garbage written by white kids who watch too much Naruto and a few bs-"martial arts gurus" who can't even speak Japanese, much less have "aquired the secrets of the ninja" from old Japanese mountain men hiding behind reed mats ~_~;
Ninjas are like Santa Claus... yeah... there's a tiny grain of truth to it: but the bullshit pearl it's created has no equal.
Ninjutsu - Wikipedia, the free encyclopedia
a wikipedia article WITH actual souces that might dim your enthusiam for faux Japanese history