1 Mon 'Engi Tsūhō' - Daigo

The Engi Tsūhō was authorized in 907 under Emperor Daigo as part of Japan's imperial coinage program, but it proved to be the last copper cash coin Japan would officially mint for nearly seven centuries. The Heian court's fiscal apparatus collapsed shortly after, and by the mid-10th century the government had effectively abandoned metallic currency in favor of rice and silk as exchange media. Coins from this issue that show genuine circulation wear are therefore paradoxically rare — most examples were hoarded or deposited ritually rather than spent.