It is said that Kanzaemon I Ishizaki, the grandfather of Soemon-Noriaki who is the originator of Okikamuro Tomozawa Family, re-reclaimed the Okikamuro Island in 1606 (Keicho 11th). Around 1985, descendants of Ishizaki and Tomozawa Families edited their family trees named “Ishizaki So-keifu”, which contains descriptions about the origin of Kanzaemon I. It was edited based on the following sources.
• Ishizaki-Kafu, the family tree of Gogo-shima Ishizaki Head Familiy, Tomari, Gogo-shima Island, Matsuyama, Ehime
• The family tree of Yuu Ishizaki Family, Yuu, Yashiro-jima Island (Suoh Big Island)
• Ishizaki-Keifu, the family tree of Okikamuro Ishizaki Head Family, which was edited by Kanzaemon VI and the 7th priest of Hakusei-ji temple Banryu in 1763
• Tomozawa Kakeizu Ryakuden, the family tree of Mitajiri Tomozawa Family, Hofu, Yamaguchi
According to these documents, Ishizaki people were descendants of Nakamura Family who were lords in Tohoku area, moved to Iyo (Ehime) in Nambokucho era (around 1360), and served Kohno Family.
In family trees in these documents, however, obvious discrepancies of ages and insertions by posterity were found. Although I am one of the descendants of Okikamuro Tomozawa Family, I do not think objectively that the ancestors of Ishizaki people were Nakamura Family in Tohoku area.
Shirosaburo-Terumune Ishizaki, who seems to be the father or grandfather of Kanzaemon I, is said to have been a lord of Akezawa Castle in Gogo-shima Island. However, this story also seems to be unfounded.
Although Ishizaki Family is said to have been a vassal of Iyo-Kohno Family, I have never seen the name Ishizaki or Tomozawa in books specialized in Iyo-Kohno Family. In Kohno Bugenroku (official record of Iyo-Kohno Family) of Tensho 3rd (1575), the period of the last lord, “Kenmotsu Ishizaki, a chief secretary” and “Yoichi Ishizaki, a resident in Ukena County” were recorded. As one theory holds that Ishizaki Family originated in Ishizaki, Ukena County, maybe there were Ishizaki people among vassals of Iyo-Kohno Family. However, it is unclear whether or not they were related to Ishizaki/Tomozawa people in Gogo-shima and Okikamuro. In my opinion, Ishizaki Family in Gogo-shima and Okikamuro was in fact a group belonging to Murakami-Suigun navy, rather than a direct vassal of Iyo-Kohno Family.