now this is just a question in regards to the 3 ryu-ha mentioned, i was reading in one of Hatsumi Soke's books titled "Way of the Ninja" "secret techniques" and under the passage titled "Ninjutsu Diversity" Hatsumi Sensei mentions that Gyokko Ryu, Gikan Ryu and Koto Ryu are Ninjutsu schools i can understand Gyokko Ryu and Koto Ryu but not so much with Gikan Ryu what does everyone else think.
-Giuseppe