Essence of Ninjutsu Book by Masaaki Hatsumi Kyuzo Mifune we see that there are

we see that there are only 10 primary directions to attack with kicks and knee strike and know the three techniques to block

Rotations and Acrobatics 1 to 12

two-handed hold

and what kind of energy you are getting from your opponent

One of the most accomplished competitors of his generation

Essence of Ninjutsu Book by Masaaki Hatsumi Kyuzo Mifune we see that there areLooking back almost 1,000 years, the mists of Japan's chaotic past shroud the development of a way of life, an ancient struggle waged against fierce feudal lords who ruled the island nation with swords of steel and a code of death before dishonor. The people of the mountainous regions of what is now Iga prefecture wanted to live in peace, but their lords had other plans so the people learned the martial arts of self defense and used their meager farm