The Ninja heritage is over a thousand years old,less than 200
years ago a group of families known as 'Ninja' almost became
extinct and for the next few generations fought to say
alive.Finally,in the last quarter of the 20th century,the long
forgotten art of ninjutsu resurfaced headed by Masaaki Hatsumi,the
34th grandmaster in an unbroken like of student-teacher
relationship.
Ninjutsu was then not a Martial art but a way of training
'Nin'meaning endurance or perseverance and 'Jutsu meaning
method.Ninja forefathers than began to compile information and
techniques from as many different sources as possible,once compiled
and internalized,these skills were taken into battlefield.The few
warriors to return were able to log into history only those
techniques that worked.
The difference between Jutsu and Do is that the suffix Jutsu is
used in ancient times to describe martial forms that are combat
orientated ,hence you have Taijutsu,Kenjutsu,Bojutsu...etc and the
Do form which includes Karate-do,Judo,Aikido..and Ninja-do
(Wattafuck!) have their primary purpose a spiritual quest for self
developement and to a certain degree allow students to test their
skills in competitive matches.