We have seen Ninjas in movies, cartoons and all. As the speculation continues whether they are real or not, it can be impossible to say yes or not considering that they are ninjas after all. The name itself means "hidden well." Still let's take a look what we know so far.
Ninja first appeared in literary works like poems, novels, and folktales during the Meiji era. They started to credit the supernatural capacities we find in mainstream society today. The most solid records initially show up in the fifteenth 100 years. Eve to this date rumors covering Ninjas still continue.
A man named Jinichi Kawakami, a 63-year old engineer, is probably Japan’s last ninja. He’s the head of the Ban clan, a family that traces its ninja roots back 500 years. He continues sharing his skills for over 50 years with ninjutsu training and all.
The idea seems like a fantasy though, considering in real life they could be burglars, farmers, and other members of the lower castes. In addition to swordsmanship and martial arts, ninjas would fight by using covertness and trickery, so they had to be able to blend in with an enemy army, which high-ranking officers couldn’t do.