1 Mon 'Kan'eitsūhō' reverse 元 GEN

The Kan'ei Tsūhō series had been in continuous production since 1636, but the variant carrying the reverse character 元 (Gen) was introduced in 1741 as part of an effort to track output across the expanding network of authorized mints. By the mid-eighteenth century, production was distributed across multiple locations — including Edo, Osaka, Sendai, and domain-operated facilities — and reverse characters served as a practical administrative device rather than a mark of prestige. The Gen reverse is associated with the Sakamoto mint in Ōmi Province.