What is "bujinkan"

The Bujinkan (武神館) is an international martial arts organization based in Japan and headed by Masaaki Hatsumi. The combat system taught by this organization comprises nine separate ryūha, or schools, which are collectively referred to as Bujinkan Budō Taijutsu. The Bujinkan is most commonly associated with ninjutsu. However, Masaaki Hatsumi uses the term Budo (meaning martial way) as he says the ryūha are descended from historical samurai schools that teach samurai martial tactics and ninjutsu schools that teach ninja tactics.