宮古列島
It is said that Akahachi was born on Hateruma Island, and that he was large and physically strong even as a child. He moved to Ishigaki Island as a young adult, and became the chief of Ōhama Village (today part of Ishigaki City) soon afterward. His influence soon extended over all of Ishigaki Island, and beyond, to other islands in the Yaeyama Islands group. At some point late in the 15th century, the nearby Miyako Islands were divided between two influential families, the Nakasone and Kaneshigawa, who were fighting one another for dominance of the area. Seeking to take advantage of the chaos and disunity, Akahachi proposed an invasion of the Miyako Islands. However, Nakasone Toyomiya led a counterattack against Akahachi, overwhelming his forces and moving on to attack Yonaguni Island as well.