kwaichang
Purple Belt
By our definition, it is the arts taught by the current Grandmaster, Dr. Maasake Hatsumi. It also includes those groups which split off from Dr. Hatsumi but still remain true to the core ideals.
Please see the Ninja FAQ for more in-depth descriptions.
There are three main organizations. The Bujinkan, Genbukan and Jinenkan.
This forum is for the discussion of the history, techniques, concepts and ideas that relate directly to these groups.
Well the Japanese Government has *certified* the 900 yr old scrolls that Dr. Hatsumi has, proving his (Tokakure) lineage. No other school (ryu) can say the same.
The Koga-Ryu, went extinct when it's last grandmaster didn't pass on his scrolls or endorse a ligimate successor so that knocks out a bunch of people who claim that school as theirs.