Like Japan had also done for centuries, the Ryukyuans often made use of the already-existing Chinese cash coins when physical currency was needed.

In the 14th and 15th centuries, the Kingdoms of Chūzan and Ryukyu produced their own coinage, but eventually transitioned back to Japanese mon and Chinese wén.

The Sekō Tsūhō was originally cast to make up for a shortage of currency often attributed to reckless politics and high government expenditure, such as the expensive invasion of Kikai Island by King Shō Toku in the 1460s.

[8] Starting in 1862, daimyō Shimazu Nariakira of Satsuma Domain ordered for the production of coinage known as Ryūkyū Tsūhō (琉球通宝, "Ryukyu Currency").

These efforts were successful, and the Ryūkyū Tsūhō entered wide circulation not only in Satsuma, but also in Japan's other provinces soon after their production.

As these coins were minted in Satsuma Domain, they bear the mark of the katakana character "sa" (サ) stamped on their edge.

Its obverse has the words Ryūkyū Tsūhō (琉球通寳, "Ryukyu Currency"), and the reverse has tō hyaku (當百, "worth 100 [mon]").

Its obverse has the words Ryūkyū Tsūhō (琉球通寳, "Ryukyu Currency"), and the reverse has han-ju (半朱, "half shu").