Tem Po Tsu Ho written vertically // To Hyaku ("Value 100 (mon)"), signature of the mint official below. 49mm long, 19.78 grams. Cast in Honza in Edo, Musashi Province. Hartill 5.7.

Ko Kaku ("Broad hole" type), with a thick inner rim, cast 1846-1869.

The "Tempo Tsuho" ("Currency of the Tempo era") was a large denomination cast copper coin issued by the Tokugawa shogunate in 1835 (6th year of the Tempo era), with a face value of 100 mon. Oval in shape and significantly larger than earlier coins, it measured about 49–51 mm in height and was introduced to address the need for higher-denomination currency amidst economic strain. Despite its face value, the intrinsic value of the copper was much lower, leading to widespread inflation and limited acceptance in some regions. The obverse bore the inscription Tempo Tsuho in Chinese-style characters, while the reverse often showed the value “百” (100) and mint marks indicating production sites. Though intended to streamline commerce, the coin’s overvaluation eventually undermined confidence in the currency system, highlighting the broader fiscal challenges of late Edo-period Japan.