Kaidā glyphs

Kaidā glyphs (Kaidā ji (カイダー字^?)) are a set of pictograms once used in the Yaeyama Islands of southwestern Japan. The word kaidā was taken from Yonaguni, and most studies on the pictographs focused on Yonaguni Island. However, there is evidence for their use in Yaeyama's other islands, most notably on Taketomi Island. They were used primarily for tax notices, thus were closely associated with the poll tax imposed on Yaeyama by Ryūkyū on Okinawa Island, which was in turn dominated by Satsuma Domain on Southern Kyushu.

Sudō (1944) hypothesized that the etymology of kaidā was kariya (仮屋^?), which meant "government office" in Satsuma Domain. This term was borrowed by Ryūkyū on Okinawa and also by the bureaucrats of Yaeyama (karja: in Modern Ishigaki). Standard Japanese /j/ regularly corresponds to /d/ in Yonaguni, and /r/ is often dropped when surrounded by vowels. This theory is in line with the primary impetus for Kaidā glyphs, taxation.

Immediately after conquering Ryūkyū, Satsuma conducted a land survey in Okinawa in 1609 and in Yaeyama in 1611. By doing so, Satsuma decided the amount of tribute to be paid annually by Ryūkyū. Following that, Ryūkyū imposed a poll tax on Yaeyama in 1640. A fixed quota was allocated to each island and then was broken up into each community. Finally, quotas were set for the individual islanders, adjusted only by age and gender. Community leaders were notified of quotas in the government office on Ishigaki. They checked the calculation using warazan (barazan in Yaeyama), a straw-based method of calculation and recording numerals that was reminiscent of Incan Quipu. After that, the quota for each household was written on a wooden plate called itafuda or hansatsu (板札^?). That was where Kaidā glyphs were used. Although sōrō-style Written Japanese had the status of administrative language, the remote islands had to rely on pictograms to notify illiterate peasants. According to a 19th-century document cited by the Yaeyama rekishi (1954), an official named Ōhama Seiki designed "perfect ideographs" for itafuda in the early 19th century although it suggests the existence of earlier, "imperfect" ideographs. Sudō (1944) recorded an oral history on Yonaguni: 9 generations ago, an ancestor of the Kedagusuku lineage named Mase taught Kaidā glyphs and warazan to the public. Sudō dated the event to the second-half of the 17th century.

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