The Kan'ei Tsūhō series was authorized in 1636 under the Tokugawa shogunate as part of a broader effort to standardize currency across a fragmented monetary system still relying on a patchwork of older Chinese-style cash coins and regional issues. By the 1660s, numerous private and domain mints had received casting licenses, producing coins of wildly inconsistent quality — the reverse 文 (bun) mark was introduced specifically to distinguish output from the Sakamoto mint in Ōmi Province. The three DHJ references reflect documented die variations among survivors, not separate issues.
The Kan'ei Tsūhō series was authorized in 1636 under the Tokugawa shogunate as part of a broader effort to standardize currency across a fragmented monetary system still relying on a patchwork of older Chinese-style cash coins and regional issues. By the 1660s, numerous private and domain mints had received casting licenses, producing coins of wildly inconsistent quality — the reverse 文 (bun) mark was introduced specifically to distinguish output from the Sakamoto mint in Ōmi Province. The three DHJ references reflect documented die variations among survivors, not separate issues.