One-sen ceramic coin

In the twentieth year of Shōwa, with the metal for coinage used up, a plan to fire coin from potter's clay was set moving. At the kilns of Arita, Kyoto and Seto the one-sen ceramic coin was formed to a diameter of 15 millimetres, and 700 million pieces were planned. Mass production was reached in July, but the fifteenth of August came before the number needed was ready. In law not a single piece was ever issued, and most were crushed.