bujinkan

Bujinkan is a martial art system put togather by soke Masaaki Hatsumi. This was done by combining the 9 ryu he is soke of. Three of these ryu are of pure ninjutsu, and from the beginning the system was called Bujinkan Ninpo Taijutsu. Later the ninpo was dropped, due to all the negativity regarding ninjas spread through movies and TV. Instead he renamed it to Bujinkan Budo Taijutsu, indicating that it contains more than ninjutsu.

http://www.bujinkan.com/

The international training organization of Masaaki Hatsumi. Founded in the late 70's, it's dojos teach Bujinkan Budo Taijutsu all over the world. The name, roughly translated, means House of the Divine Warrior.

Each dojo is lead by a shidoshi, who oversees training, and awards grades. Classes are often taught by the shidoshi, although sometimes senior students teach as well.

Most Bujinkan Dojos follow a system of 9 kyu grades, which are then followed by 15 dan grades.