1 Ryō 'Hōei Koban' Reverse 乾 KEN

The Hōei Koban was struck in response to a currency crisis engineered — or at least exploited — by the financier Ogiwara Shigehide, who oversaw a series of debasements beginning in 1695 that flooded the economy with lighter, lower-purity gold coins. The Hōei issue partially reversed this, raising fineness back toward earlier Keichō-era standards, though it never fully recovered them. Ogiwara was ultimately dismissed in 1712 under pressure from the Confucian scholar Arai Hakuseki, whose economic reforms shaped the final years of this type's production.

The reverse character 乾 designates one of two certification marks used on this issue, the other being 坤.