Utdrag fra Kacem Zoughari’s bok: Ninja – Ancient Shadow Warriors of Japan:
«In the first year of the Huang Du era (corresponding to the Kûyû era i Japanese, the year 1049), Ikai of the Sijang province, who was defeated by the armies of Ren Zong, Qidan (916-1125) and of Xia (1038-1227), was exiled to distant Japan.
He arrived in the province of Ise and lived in a cave in the province of Iga. The transmission document of the school indicates that Ikai was a general who excelled in hichô ongyo no jutsu (combat techniques based on «hidden kicks»).
According to this document, the basis for ninjutsu was established by «naturalized» Chinese like Ikai, Yô Gyokko, and Chô bushô, who disseminated (among other things) hichô-jutsu (combat techniques based on kicks), tôte-koppô-jutsu (art of unarmed combat based on Chinese bone-breaking techniques), and Senban-nage-jutsu (shuriken throwing techniques).
Spesifically, the Gyokko-ryû kosshi-jutsu school spawned the following schools: Kotô-ryû koppô-jutsu, Gikan-ryû koppô-jutsu, and the Gyokushin-ryû koppô-jutsu.
Moreover, if one considers the way that the fifty-three families of Kôga-ryû ninjutsu as well as the thirty-eight families of Iga-ryû ninjutsu developed happô-biken-jutsu (combat techniques based on the eight secret laws governing the art of the sword) from the Gyokko-ryû school, it can be argued that the aforementioned schools lie at the origin of Japanese martial-arts.
During the Jôho era (1074-1077), the document reports that Ikai had two pupils called Gamon Dôshi and Hôgen Tesshin. Ninjutsu was established during the fifty years that separate the Manjû and Jôho eras.