Yonaguni (Yona Country) was an ancient state that once existed on Yonagunijima (Yonaguni Island) at the westernmost end of Okinawa Prefecture. The oldest archeological remains verified there are the Tsuguruhama-Iseki. They were thought to be from the late Eolithic age, but recent research shows they may date back to 4400 years ago.

No earthenware has been excavated from this site, which suggests that the people who lived here practiced a culture where pottery was not used. In recent years, further sites have been discovered that lie under water, which may lead to some interesting correlations.

The history of Yonaguni is still vague, but it is known that in the 11th century, the people living in this country established settlements on plateaus. It is also thought that in the 14th century the culture and civilisation of Yonaguni further developed as a result of its position as a marine crossroads.

In 1522, Yonaguni was ruled by the empress Sanai Isoba, but fell before vanishing completely under the domination of the Ryukyu Dynasty. The lost history of Yonaguni is still wrapped in a mystery, and leaves many questions unsolved.