Mameita gin, which means “bean-plate silver,” was a unique type of Japanese coin that circulated from the early to mid-17th century. Recognized for their distinctive shape and role in commerce, mameita gin served as practical artifacts of Japan’s economic history and fascinating examples of localized currency under the Tokugawa shogunate.
Historical and Legal Context
During the early Edo period, Japan’s monetary system was fragmented, with a patchwork of regional coins, silver bullion (chogin), and token forms of value in circulation. The Tokugawa shogunate recognized the need for standardized Japanese coinage to facilitate commerce in an increasingly urbanized society. Over sequential eras, such as Keichō (1596–1615), Shōhō (1644–1648), and Genbun (1736–1741), the central government issued decrees controlling the specifications of silver coins, including the mameita gin. Such measures set standards for weight, size, and purity, and required official authorization for any minting.
Physical Characteristics and Design
Mameita gin stood out for its irregular, bean-like shape, which was typically oval, sometimes lumpy or flattened, frequently displaying the marks of hand-manufacture. They generally measure approximately 2.1 to 2.5 centimeters in length (with some variation), and their typical weight is in the range of 1.7 to 3.1 grams, depending on era and specific issue. Pieces heavier than about 3.1 grams are more appropriately classified as itagin (板銀, rectangular silver plate coins) or, if around 8.6 grams and with specific distinguishing marks, as ichibugin (一分銀), a distinct and much larger denomination. It is important not to confuse these larger coinages with mameita gin: the “mame” (bean) name always refers to a relatively small coin.
Designs on mameita gin were minimal but purposeful, emphasizing authenticity and official manufacture. Most issues bore the character 銀 (gin, “silver”), sometimes accompanied by symbols referencing the issuance era, such as 文 (Bun) for Genbun or 寳 (Ho) for Tenpo, or a mint mark. However, many mameita gin display only the gin character and may lack era or locus attribution entirely, which complicates precise dating and cataloguing.
These visible features, when combined with hand-finishing, enabled merchants and consumers to distinguish legitimate mameita gin from forgeries or regional imitations, and promoted widespread trust in the coin’s authenticity within the market.
The Design Process and Practical Role
Mameita gin was made using distinct manual and traditional techniques. Silversmiths melted and poured silver alloy into molds (wooden or cloth), cut, hammered, and flattened each piece into its signature bean-like form, and then impressed official marks by hand. Each specimen is unique in detail, and this “irregular irregularity” was accepted as proof of individual manufacture and authenticity. Their form, size, and surface texture all aided in swift identification and validation, an essential quality for Japan’s bustling, cash-driven markets where rapid transactions and physical handling of coins were the norm.
Production, Purity, and Value
Although many Mameita gin contained a significant percentage of silver, actual fineness varied greatly by era and decree. Standard Edo-period mameita gin usually contained 60-80% silver.
Economic Role, Decline, and Legacy
Throughout the Edo period, mameita gin were indispensable for small-to-medium-sized purchases—serving as transactional currency in a system where larger silver plate (chogin) or gold koban were reserved for higher-value exchanges. Their standardized size, ragged shapes, and particular silver content made them ideal for daily market trade.
Today, mameita gin coins are prized by numismatists and historians as tangible reminders of early modern Japan’s decentralized yet resilient monetary order. Their irregular form, local “character,” and capacity for practical adaptation stand as testimony to the ingenuity of their makers and the society that depended upon them.
Mameita gin encapsulate the creativity, pragmatism, and adaptability of Tokugawa Japan’s approach to money. More than mere relics, these small, bean-shaped silver coins form a living bridge between art, commerce, and the shifting political landscapes of Japanese history—an enduring symbol of the country’s monetary ingenuity and a unique chapter in the history of world coinage.
