Ōōso (汪応祖) was a local ruler of Okinawa Island, who was given the title of King of Sannan.
He first contacted the Chinese emperor in 1403, claiming himself to be a younger brother or cousin of Shōsatto, the late King of Sannan, who reportedly had no son.
A desperate attempt of decipherment relates it to Yaese (八重瀬), a fortress in southern Okinawa.
[3] Similarly, historian Wada Hisanori suspects that Ōōso was not a younger brother or cousin of King Shōsatto and that it was a made-up story to eliminate Chinese suspicion.
Based on the assumption that by that time, Shō Hashi, the unifier of Okinawa Island, had already kept Sannan under his control, Wada claims that Ōōso was either a pseudonym of Shō Hashi or his puppet ruler.