The Rationale of 'Write 100, and It Becomes 100 Mon'

A Coin Inscribed with 'One Hundred'

In the sixth year of the Tenpō era (1835), the casting of a peculiar coin began at the Edo kinza, or gold mint. This was the Tenpō Tsūhō. It had an oval shape reminiscent of a koban, with a length of approximately fifty millimeters. The reverse was inscribed with the characters "Tō Hyaku" (Worth One Hundred) and the kaō, or stylized signature, of the Gotō family, who oversaw the kinza.

Its weight was 5 monme and 5 fun, approximately 20.6 grams. As a material, however, it was worth only as much as five or six one-mon coins. While its face value was set at one hundred mon, it is said to have circulated in the cities at an actual value of about eighty mon. The gap between its face value and intrinsic value was enormous. If it had circulated at its full face value, the difference would have become entirely the shogunate's profit.

In the Midst of Famine

Shortly before this coin was created, starting in the fourth year of the Tenpō era (1833), the country was struck by a famine caused by cold weather and heavy rains. In five years, the population decreased by 1,252,000, and in Osaka, more than 150 to 200 people were starving to death daily.

Even in such conditions, the East Town Magistrate, Atobe Yoshisuke, continued to send rice from Osaka to Edo to cover the costs of the shogun's investiture ceremony scheduled for the following year. In response, Ōshio Heihachirō, a former police sergeant and Yōmei-gaku scholar, sold his book collection after his proposals were rejected and distributed relief tickets, exchangeable for one shu of gold, to ten thousand needy people. Then, in the eighth year of the Tenpō era (1837), he raised an army of about three hundred followers and attacked the storehouses of wealthy merchants. The rebellion was suppressed in half a day, but one-fifth of the city of Osaka was burned to the ground.

Who Was Raising the Prices?

The shogunate, through the issuance of the Tenpō Tsūhō and the recoinage of koban and ichibugin silver coins, had gained a profit of over five million ryō in just over five years. Prices continued to rise. The rōjū, or senior councilor, Mizuno Tadakuni, who began his reforms in 1841, believed the cause lay with the kabunakama, or trade guilds, which monopolized business, and ordered their dissolution.

The result was the opposite. The distribution networks were severed, the flow of goods into Edo dwindled, and the economy slumped. Ten years later, the shogunate itself rescinded this order. It was not the monopolies that had been raising prices. It was the coins the shogunate itself had minted.

The Shogunate's Coin, Minted by the Domains

The shogunate used the rationale that "if you write one hundred, it becomes one hundred" in its crudest form. Eventually, various domains began to secretly mint these coins themselves. The hirokaku, or "wide rim" variety, minted by Satsuma is well-known by that name.

At the end of the shogunate, the treasuries of the various domains were empty. To cover the costs of buying warships and procuring guns, they began to produce currency itself, a right that originally belonged solely to the shogunate. It is said that Satsuma's counterfeiting of the Tenpō Tsūhō began around the Kaei era (1848–1854). According to one estimate, this would amount to over 75 billion yen in today's value. Counterfeiting was not limited to Satsuma; Aizu, Nagoya, and Matsushiro also engaged in it. There were counterfeit coins in the coffers of both the imperial army and the shogunate army.

The new nation was forced to first remake its currency. This was because in the second year of the Meiji era (1869), foreign envoys protested the counterfeit currency in circulation.