---
title: "Bunsei Koban"
url: "https://ittendo.com/en/coinpedia/edo-gold-012-bunsei-koban"
site: "ITTENDO"
type: "coinpedia"
category: "edo-gold"
series: "Edo Gold Coins"
lang: "en"
---
# Bunsei Koban

> Conclusion: Bunsei Koban, with its stable price range and abundant existing specimens, is an ideal "red gold" for beginners in coin investment.

- 時代: 江戸
- 素材: 金
- 額面: 両 / 分 / 朱
- 発行量: 大量
- 価格帯: 普及

## Background and Historical Context of the Bunsei Koban

The Bunsei Koban (文政小判) began to be minted in Bunsei 2 (1819), during the late Edo period. This era fell under the rule of the 11th shogun, Tokugawa Ienari, and was known as the "Ōgosho Jidai" (era of the retired shogun). The shogunate was suffering from serious, chronic budget deficits. As a primary means of overcoming these financial difficulties, the shogunate came to rely on acquiring seigniorage (差益, saeki) through currency recoinage. The Bunsei Koban was issued with a significantly reduced gold fineness compared to its predecessor, the Genbun Koban (元文小判), and the resulting profit became an important source of revenue for the shogunate.

This recoinage was not merely a currency update; it was closely tied to the socioeconomic conditions of the time. Repeated recoinages caused fluctuations in monetary value and contributed to price inflation. The Bunsei Koban became widely known by the popular nickname "Sōbun-kin (草文金)" because of the cursive-script (草書体) character "文" stamped on its reverse. It is estimated that more than approximately 1.1 billion of these koban were minted, suggesting they had a profound impact on the economic activity of the period. The Edo-period monetary system as a whole is explained in detail in [Edo Gold Coins (Koban & Ōban) Introduction](/coinpedia/edo-gold-001-overview).

## Basic Information and Characteristics of the Bunsei Koban

The Bunsei Koban is clearly distinguished from other koban by its physical characteristics. The most prominent feature is the cursive-script (草書体) "文" stamp struck on the reverse. The brushstroke style of this character differs greatly from the regular-script (楷書体) "文" of the preceding Genbun Koban, making it an important point of identification. The weight (量目) was maintained at 13.1 g, the same level as the Genbun Koban, but the gold fineness declined to approximately 56% (as recorded: Genbun 66% → Bunsei 56%), giving the coin a slightly reddish hue.

This reddish tint results from the increased proportion of silver relative to gold, and among numismatic enthusiasts the coin is sometimes described as "aka-kin" (赤金, red gold) or "aka-koban" (赤小判, red koban). The dimensions are approximately 66 mm vertically × 36 mm horizontally, an oval shape virtually identical to that of the Genbun Koban. However, the difference in color is immediately apparent, and this distinctive reddish tone has become a symbolic characteristic of the Bunsei Koban. The obverse bears the characters "壹両" along with the signature of Mitsutsugu (後藤家, the Gotō family), while the reverse carries a date stamp and a flower seal (花押).

## Details of Gold Fineness and Weight

The gold fineness of the Bunsei Koban is 56.4%, representing a substantial decline of approximately 8.9 percentage points from the Genbun Koban's 65.3%. Because the weight was held at 13.1 g, the pure gold content per coin is approximately 7.4 g. Compared to the approximately 8.5 g of the Genbun Koban, this represents a reduction of approximately 1.1 g of pure gold. The alloy ratio of 56.4% gold to 43.6% silver produces the reddish-toned color distinctive to the Bunsei Koban.

This color serves as one important clue in the authentication of old coins; however, because the surface tone can vary depending on aging and storage conditions, judgments based on color alone should be avoided. If one assumes gold at 10,000 yen per gram, the bullion value of a single Bunsei Koban would be approximately 73,000 yen (weight 13 g × fineness 56%), though the market value as a numismatic piece generally far exceeds its bullion value. The factors that determine the value of old coins are explained in detail in [Factors That Determine the Value of Old Coins](/coinpedia/basics-001-value-drivers).

## Authentication Points: The Cursive-Script "文" Stamp

The single most important authentication point in identifying the Bunsei Koban is the cursive-script (草書体) "文" stamp struck on the reverse. The brushwork of this character differs entirely from the regular-script (楷書体) "文" of the preceding Genbun Koban in stroke order and form, and is characterized by flowing curves and continuous brushstrokes. The cursive "文" appears as though the dot and horizontal stroke are connected, and it carries a distinctive energy of the brush.

Reproducing this delicate cursive script is considered extremely difficult and is said to be the part that causes counterfeiters the most trouble. The stamp on a genuine Bunsei Koban has a natural, single-stroke-like flow, with uniform engraving depth and a powerful impression. Counterfeits, by contrast, tend to show unnatural breaks in the brushstroke or uneven engraving depth. Accurately understanding the differences between the two by comparing the Genbun Koban's regular-script "文" with the Bunsei Koban's cursive version is essential basic knowledge for old-coin collecting. Detailed information on identifying fakes can be found in [Complete Guide to Identifying Fakes and Altered Coins](/coinpedia/basics-004-fakes).

## The Reign of the 11th Shogun Tokugawa Ienari and the Deterioration of Shogunate Finances

The late Edo period during which the Bunsei Koban was minted overlaps with the reign of the 11th shogun, Tokugawa Ienari (1793–1837). Ienari held the position of shogun and later retired shogun (大御所) for nearly 50 years, establishing a long-ruling administration known as the "Ōgosho Jidai." However, his lavish lifestyle and the severe burden that a large number of children placed on shogunate finances were serious problems. The shogunate suffered from chronic budget deficits, and the practice of acquiring seigniorage through currency recoinage to make up the shortfall became routine.

The Bunsei recoinage was likewise carried out as a means of temporarily papering over this fiscal deterioration. While reducing the gold fineness brought the shogunate large profits, it simultaneously caused a decline in monetary value and price inflation in the marketplace, creating the side effect of burdening the lives of ordinary people. The economic policies of this period might be said to have aimed at short-term fiscal recovery while sowing the seeds of long-term economic disorder.

## Comparison of the Bunsei Koban with Other Koban

It is important to understand the Bunsei Koban within its relationships to the preceding Genbun Koban and the subsequent Tenpō Koban (天保小判) and Ansei Koban (安政小判) within the cycle of currency recoinages in the late Edo period.

*   **Genbun Koban (元文小判) (before Bunsei 2):** Gold fineness 65.3%, weight 13.1 g. The Bunsei Koban has the same weight but a fineness 8.9 percentage points lower. The difference in pure gold content is approximately 1.1 g, and the Genbun Koban tends to command a higher market evaluation. In a comparison of average-grade (並品) specimens, the Genbun Koban trades in the 400,000-yen range while the Bunsei Koban trades in the 300,000-yen range, a price difference of approximately 100,000 yen.
*   **Tenpō Koban (天保小判) (successor to the Bunsei Koban):** Gold fineness 56.4%, weight 11.2 g. The fineness is the same as the Bunsei Koban, but the weight is 1.9 g lighter. In terms of pure gold content, the Bunsei Koban exceeds the Tenpō Koban.
*   **Ansei Koban (安政小判) (successor to the Tenpō Koban):** Gold fineness approximately 57%, weight approximately 9 g (as recorded). A koban that symbolizes the extreme decline in fineness at the end of the Edo period.

The Bunsei Koban, Tenpō Koban, and Ansei Koban are frequently compared and collected together as the "Bakumatsu Three Koban," and there are not a few enthusiasts who find special value in assembling all three for their collections. Details on the types of koban and their respective price ranges can be confirmed in [Types of Koban and Their Price Ranges](/coinpedia/edo-gold-002-koban-types).

## The Nickname "Sōbun-kin" and Its Meaning

The Bunsei Koban is called "Sōbun-kin (草文金)" because the "文" character of the stamp engraved on its reverse is rendered in cursive script (草書体). This nickname is not merely a label for identification; it also represents an interesting aspect of how people of the time perceived and distinguished their currency. Because the "文" on the preceding Genbun Koban was in regular script (楷書体), it is thought that the name arose naturally to clearly differentiate the two.

The name "Sōbun-kin" was widely used even among ordinary people of the time and was deeply rooted in currency circulation and daily life. This nickname suggests that the visual characteristics of a coin were shared among the populace and formed part of a coin's identity, alongside specialized information such as fineness and weight. For modern collectors as well, the nickname "Sōbun-kin" is an important keyword for understanding the historical background and cultural value of the Bunsei Koban.

## Caution Regarding Counterfeits and Forgeries, and Methods of Detection

Because the Bunsei Koban circulated in large numbers, a relatively large number of counterfeits and forgeries also exist. Particularly worthy of attention are "altered pieces" (改造品) in which the weight of a Tenpō Koban has been increased. There is a weight difference of approximately 1.9 g between the Tenpō Koban (weight 11.2 g) and the Bunsei Koban (13.1 g). Accurate weighing alone makes it possible to detect many altered and counterfeit pieces. Use a digital scale to measure the weight and check for any deviation from the standard value.

Sophisticated imitations of the cursive-script "文" stamp also exist. However, whereas the genuine strike has uniform force and depth with a natural flow of brushstrokes, counterfeits tend to show uneven engraving depth or unnatural breaks in the brushstroke. Furthermore, any deviation from the 56.4% gold fineness—for example, if X-ray fluorescence analysis indicates below 50% or above 65%—strongly suggests the possibility of a counterfeit. It is wise to verify multiple checkpoints comprehensively and to request authentication by a specialist. For detecting counterfeits among old coins, please also refer to [Guide to Detecting Fakes and Altered Coins](/guide/fake-detection).

## Position in the Collecting Market and Price Range

Because the Bunsei Koban was minted in very large numbers among the late-Edo-period koban and surviving examples are plentiful, it is one of the relatively accessible coins in the old-coin market. Its accessibility makes it popular as the first koban many beginners acquire.

Because the coin was minted relatively close to the end of the Edo period, it is also characteristic that many specimens surviving in comparatively good condition exist. However, specimens on which the cursive "文" stamp on the reverse is indistinct tend to be evaluated lower. When considering a purchase, it is important to prioritize confirming the sharpness of the stamp, the degree of surface wear, and whether the "ubu-iro" (うぶ色)—the natural color tone from the time of manufacture—is preserved. Methods of purchasing in the market are explained in detail in [Guide to Sources and Methods for Acquiring Old Coins](/coinpedia/basics-008-shotai).

Individual prices and auction results are listed only once verifiably matched records — with sale, lot, source URL and review date — exist.

## Historical Significance of the Bunsei Koban and Its Value Today

The Bunsei Koban is a coin that symbolizes the financial difficulties of the shogunate in the late Edo period and the response of currency recoinage taken against them. It is a precious historical document that speaks to the economic conditions of the "Ōgosho Jidai" under the 11th shogun Tokugawa Ienari, and it is an indispensable presence for reflecting on the impact that repeated recoinages had on the lives of ordinary people. Its mass minting and wide circulation demonstrate the scale of the economy of the time and the reality of how deeply currency had permeated society.

In the modern era, the Bunsei Koban holds value not merely as a lump of precious metal, but as a "living witness to history" conveying the economy and culture of Japan approximately 200 years ago. For collectors, its distinctive reddish color tone and the cursive-script "文" stamp are its attractions; for history enthusiasts, it serves as a window through which one can glimpse the shogunate's fiscal policies and the lives of ordinary people. Given its accessible price range and plentiful surviving numbers, its significance as an entry point through which many people can come into contact with Japan's old-coin culture is immeasurable.