This coin differed greatly in shape from ordinary copper cash, being a large oval. The shogunate set its value at 100 mon,but in practice it circulated at 80 mon. As a bowl of soba—popular among commoners in Edo—cost 16 mon, it was a high-denomination coin. Although it was extremely valuable compared with other copper coins, a major reason behind its minting was to secure fundsfor measures addressing the social unrest of the time, including famines and riots.