Kancho's essay Back NO,1  館長エッセイバックナンバー1
Is Ninja exist? 忍者は存在するか? ...........................................HOME
Ninja as the superman doesn't exist.
However, "Nin-jutsu" as martial arts exists.
It is military arts of the concentration of wisdom of a Japanese race who includes even "Plot", "Firearms", "Medicine", "Arms", "Martial art", and "Philosophy".A lot of Japanese confuse Ninjutsu in the movie with Ninjutsu of martial arts. It is likely to be able to say almost.
So if  Dojo of Ninja appears in Japan, the Japanese will think joke or actor's training school.
gojuryu internatinaol karatedo kobudo union yuzenkai japan
gojuryu internatinaol karatedo kobudo union yuzenkai japan  
 Ninja is called alias "Shinobi". Actually, "Shinobi" is historically more correct. In this, Japanese words "Shinobi"+"kom" is an etymology. The meaning is "Person who invades secretly. "The special skill group named Ninja(Shinobi) existed until the age of Samurai in the 19th first half of the century. Their work is espionage. It is "Spy" said now. Therefore, Ninja doesn't combat. It is time when fight by Ninja was cornered by the enemy.
It was only a case with the possibility of getting away.In many cases, he might have committed suicide.
Ninja acquired various knowledge to conduct espionage alone. They are military arts, gunpowders, pharmacologies, chemistries, physicss, measurements, disguises, geographies, and languages, etc.A left picture is characters of Ninja Manga when I am a child (the 1960's). They moved like the "Superman".
They disappeared. They controlled the wind. They moved in the air with a big kite. They revived though they died. They were indeed absurd.
Lets think .
Man cannot do movement to transcend physics.
Ninja in the movie and or the Manga is a fantasy that man's wish invented.

In Europe and America, there seem to be a lot of Ninja Dojo. I think that the mania in Europe and America is the one that various military arts was synthesized and created.
Of course, the technique and the knowledge of old Ninja are being maintained to Japan by some people.
And, there is a little person who is teaching it as ancient martial arts, too.
However, even if they are learnt, you cannot become like Ninja that appears in the movie and Manga.
By the way,a right photograph is historically accurate Ninjya. (woman)
ninjya ninjya

(座さがしの術の図)「Zasagashi no jutsu」
Technique for invading the dark room by using sword and sheath.