Origin of the Ninjutsu
Ninjutsu (Also called Shinobi-jutsu) is a collection of techniques originally practiced for espionage purposes. It includes methods of spying, confusing, and gathering information.
The character nin/shinobi means "steal in" or "endurance".
Even though it was influenced by Chinese spying techniques, Ninjutsu is most definitely of Japanese origin. It probably came into being sometime around AD 600, while Empress Suiko was in power; Michinoue-no-Mikoto is believed to be the pioneer.
Actual Ninjutsu is rarely taught these days. The X-kan: Bujinkan, Genbukan, and Jinenkan each contain at least one complete Ninjutsu ryuha, but they also contain other koryu Bujutsu that they tend to focus on.
The only ryuha that is taught at all is Togakure Ryu. Other extant kobudo, such as the Tenshin Shoden Katori Shinto ryu, contain aspects of Ninjutsu in their curriculum; but they are not Ninjutsu ryuha per se.
Other schools, which may or may not directly relate to the genuine japanese ninja traditions, have different paths.
For example, the Temple of the Full Autumn Moon, which teaches Saito Ninjitsu (and defines Ninjitsu as something very similar but different from Ninjutsu), follows the Wu Shan Fa or "Five Mountain Path of the True Warrior Spirit."
It can be found here. It should also be noted, historians do not believe any Ninjutsu ryuha outside the X-kan to be extant, but it is up to the individual to decide.
Hachiko is more than a statue or a tale, he was a real dog who's story is known throughout Japan and the world today. The word Hachiko has come to be synonymous with loyalty, and for good reason.
The story has a few variations depending on who tells it but the basic facts are well documented.