Do Japanese Ninja's Ninjutsu Really Exist

Japanese history is the existence of ninjas, otherwise how would ninjas be one of the traditional culture of Japan? As for the ninja with the ninjutsu is what the diversion, with smoke bombs that kind of blindfold method to realize the disappearance, and legend has it that they can also float on the water, to move at a very fast speed, the weapon is more or less bitter, hand sword class it!