When Hatsumi started the Bujinkan his claim was that he was the only grandmaster of the ninja left in the world, he was the head of all 9 remaining schools, and that nobody else could possibly teach ninjutsu.
His claim was that Takamatsu, the 33rd grandmaster was the only person left who not only studied the 9 schools, but the only person he ever taught was Hatsumi.
Hatsumi was 28 when he met Tak, who was about 60. They trained for about 11 years and then Tak died.
So Hat claim is that he became the grandmaster of 9 schools in just 11 years.
He would also claim that Tak became grandmaster at 30, spent 30 years never teaching anybody and that he trained Hat for the last decade of his life.
The claim is that Tak was the 33rd grandmaster of the Togakure ryu, which was passed down through his family. He inherited the title from his grandfather.
Tak trained in Kukkishin ryu under grandmaster Ishitani.
Tak spent most of his 20s travelling through China, where he had all kinds of ninja adventures, fought against and trained with Chinese kung fu masters.
We know the gyokko ryu school of ninjutsu is heavily influenced by kung fu and it is possible Tak used kung fu training to fill out the gaps in what he knew about the ryu.
Back in japan, Tak trained as a mikkyo priest.
So what did Tak do between the ages of 30 and 60?
He was training ninjas of course.
Counter claim:
"Just coz Hat was the last person to train under Tak and got the Togakure, Gyokko and Kukkishin scrolls does not mean he was Tak's only student. It doesn't even really mean he's the grandmaster.
We know Hat buys scrolls from antique dealers so that would explain where the scrolls from the other 6 schools came from.
It is also possible Hat trained with other ninja masters, but didn't want to divulge this.
Ninjutsu was passed down father to son. It is ludicrous to suggest that all the family lines died out and ninjutsu was never passed on in it's other forms, or that other ryu do not exist.
Most ninjas do not publish books, appear in magazines, have websites and face book accounts.
Tanamure, when he left the Bujinkan, studied with other ninja grandmasters before setting up the Genbukan.
Tan lists at least 19 schools of ninjutsu that survive.
