News at Eleven: An almost legible "iroha uta" poem is inscribed

on the back of the earthenware dish, which dates back to around 1200. Iroha uta, an ancient Japanese poem that uses 47 Japanese characters only once each, is said to have been created between the late 10th century and the 11th century. The poem was used for writing practice of hiragana, Japan's basic phonetic script.

from The Asahi Shimbun: Oldest hiragana writing found on ancient pottery

~~~~~~~~~~~