The Tenpō Mameitagin was struck by the Tokugawa shogunate's silver za as a regional trade currency for western Japan, where silver was the dominant medium of exchange in contrast to the gold-based economy of Edo. The irregular, hand-struck form was deliberate — each piece was weighed individually in transactions rather than counted, a practice that had persisted in Osaka merchant culture for centuries.
The small 保 character variety is distinguished by a die-punch detail, not a separate issue. The dramatically debased silver content relative to earlier mameitagin reflects the shogunate's mounting fiscal pressure through the 1840s and 1850s.
The Tenpō Mameitagin was struck by the Tokugawa shogunate's silver za as a regional trade currency for western Japan, where silver was the dominant medium of exchange in contrast to the gold-based economy of Edo. The irregular, hand-struck form was deliberate — each piece was weighed individually in transactions rather than counted, a practice that had persisted in Osaka merchant culture for centuries.
The small 保 character variety is distinguished by a die-punch detail, not a separate issue. The dramatically debased silver content relative to earlier mameitagin reflects the shogunate's mounting fiscal pressure through the 1840s and 1850s.