--- title: "To-shimon Coins" url: "https://ittendo.com/en/coinpedia/ana-sen-008-shimonsen" site: "ITTENDO" type: "coinpedia" category: "ana-sen" series: "Holed Coins" lang: "en" --- # To-shimon Coins > Conclusion: To-shimon coins are ideal for beginners, while rare mother coins and variants also offer attractive investment potential. - 時代: 江戸 - 素材: 銅 - 額面: 文 - 発行量: 大量 - 価格帯: 普及 ## Overview and Historical Background of Tōshi Monsen Tōshi Monsen (当四文銭) is a large-diameter coin with a value of four mon. It circulated as an important coin supporting Japan's monetary economy from the mid-Edo period to the end of the Tokugawa shogunate. It followed the one-mon coin 'Kan'ei Tsūhō (寛永通宝)' which began minting in Kan'ei 13 (1636) as a higher denomination currency. The coin has a diameter of about 28mm, is made of standard copper weighing around 6 to 7 grams, slightly larger and heavier than the usual one-mon coin (about 24mm). The distinctive wave pattern on the reverse side is its most prominent visual feature, making it clearly distinguishable from one-mon coins. The standard pattern is known as 'Jūichi Nami' with eleven waves, although there are many variations. In daily transactions of common people, it simplified large payments and change-making. Especially during the economic turmoil of the late period, its role became even more crucial. Tōshi Monsen is an indispensable part of Japanese cash coin history as explained in [Introduction to Cash Coins (Kan'ei Tsūhō and Tenpō Tsūhō)](/coinpedia/ana-sen-001-overview). ## Variation in Materials: Transition of Copper, Brass, and Iron Throughout its long minting period, Tōshi Monsen was produced with various materials. Initially, it was minted as 'Kan'ei Tsūhō Seihasetsu' beginning around Kanbun 8 (1668) using copper. These early coins are known for their reddish tint and are commonly found. Later, from Genbun 1 (1736), four-mon coins made of brass (yellow copper) emerged. Brass, an alloy of copper and zinc, has a beautiful golden hue and is resistant to rust, leading to many well-preserved specimens. This change in material was influenced by the shogunate's financial situation and metal resource acquisition status. From Bunkyū 2 (1862) onward, due to financial stress and the introduction of Western casting techniques, a large quantity of iron four-mon coins was minted. Known as 'Bunkyū Eiho Iron Coins', these are noted for their gray-black color and magnetic attraction. Details on these material differences are further explained in [Types and Market Prices of Kan'ei Tsūhō](/coinpedia/ana-sen-002-kanei-tsuho) and [Bunkyū Eiho Collection Guide](/coinpedia/ana-sen-004-bunkyu-eiho). ## Appeal and Market Evaluation of Brass Four-Mon Coins Brass (yellow copper) Tōshi Monsen, known as 'Brass Four-Mon Coins', are particularly popular for their unique golden shine. As an alloy mainly composed of copper and zinc, it not only offers beauty but excellent durability. Compared to copper coins, they are less prone to rust and more resistant to verdigris, thus many coins in good condition remain. This characteristic is highly attractive to collectors. Especially coins in excellent condition that retain their mint state receive high praise as display pieces. In the market, standard brass four-mon coins usually trade for a few hundred yen, while those minted in small quantities early on or with distinctive script can be valued from several thousand yen to around 10,000 yen. Although brass coins minted in large quantities during the Bunkyū period are relatively easy to obtain, focusing on detailed designs and the beauty of patina can further deepen the collecting experience. The shine of brass is a crucial factor in assessing the ‘condition’, one of the [Factors Determining the Value of Old Coins](/coinpedia/basics-001-value-drivers). ## Variants of Wave Pattern and Depth of Appraisal The wave pattern on the reverse side of Tōshi Monsen is central to its identification and classification. The standard 'Jūichi Nami' is named for its eleven waves. However, there are actually a variety of variations in the number of waves, their depth, shape, and even the direction of their curl on the sides. For instance, some coins have deeply and clearly carved waves, while others are shallow and obscure. These differences primarily arise from the mint, time of casting, or mold wear. Some mints (e.g., Mito Sen, Kameido Sen) even exhibit unique wave expressions, becoming collection points for advanced collectors. Identifying the subtle differences in wave patterns goes beyond mere classification to infer where and when the coin was minted. The study of these minute variations is essential for understanding the concept of 'variations' in the [Variety Classification System of Old Coins](/guide/varieties) and one of the joys of collecting Tōshi Monsen. ## Diversity Observed in Script and Mints The script on Tōshi Monsen, specifically the characters '寛' '永' '通' '宝', vary depending on the mint and period. Although they may look the same at first glance, there are detailed differences in stroke thickness, flares, dot positions, and the overall balance of each character, which stimulate collectors' curiosity. For example, certain mints are known for their bold strokes, while others use more delicate standard scripts. These script differences are important clues indicating the region where the coin was produced. The fact that regional mints had unique styles showcases the diversity in the Edo period's currency system. Coins classified as 'Curiosities' or 'Unusual Coins' due to their departure from standard scripts often receive high market evaluations. Although less researched compared to one-mon coins, detailed observation and comparison can lead to new discoveries, making it an attractive exploration area for advanced collectors. ## Identifying and Valuing Mother Coins and Circulation Coins In the world of old coins, 'Mother Coins' (母銭) are the prototypes used to create molds for circulation coins and can hold high value due to their rarity. The mother coins of Tōshi Monsen are no exception. They are slightly larger (about 0.5–1mm) than circulation coins, with deeper and more vivid engravings of characters and wave patterns. Additionally, they feature finely finished rims with minimal burrs, overall crafted with precision. Their weight tends to be more than the standard for circulation coins (copper, about 6–7g), as they were made thicker and more carefully to create accurate molds. On the market, mother coins can trade from tens of thousands to hundreds of thousands of yen. Occasionally, mother coins may be mistakenly listed as circulation coins at bargain prices. With deep knowledge and keen discernment, there's a possibility of unexpected discoveries. Discovering mother coins symbolizes the importance of 'rarity', a key factor in [Factors Determining the Value of Old Coins](/coinpedia/basics-001-value-drivers). ## Key Points in Appraisal: Material, Condition, Authenticity Appraising Tōshi Monsen requires determining the material, evaluating the condition, and discerning authenticity. Material assessment involves: ① color tone (copper: reddish-orange, brass: golden, iron: gray-black), ② magnet test (iron attracts, copper and brass do not), and ③ weight measurement (iron is heavier at the same size). Specific gravity measurements aid in more accurate material identification. Condition evaluation focuses on the wear on characters and wave patterns, surface scratches, and the beauty of patina. Brass coins are often found in relatively clean condition due to their resistance to rust, whereas iron coins are prone to rust. Understanding proper [Coin Grading Standards](/coinpedia/basics-003-grading) allows for objective evaluation. Identifying authenticity involves clarity of casting marks, stroke quality of characters, intricacy of wave patterns, and weight. Modern sophisticated counterfeits and replicas exist, so careful observation for unnatural gloss or casting irregularities is essential. Referencing [Guide to Identifying Counterfeits and Replicas](/guide/fake-detection) is crucial for careful judgment. ## Proper Storage and Maintenance of Tōshi Monsen Maintaining Tōshi Monsen in good condition over long periods requires appropriate storage and care based on the material. Copper coins tend to form verdigris in high humidity, so it is recommended to store them in sealed coin capsules or slabs with desiccants like silica gel. The ideal humidity is below 50%. Brass coins are more stable than copper coins but should be kept away from direct sunlight and sudden temperature changes to avoid discoloration. Iron coins are the most susceptible to rust and require careful attention. Applying a thin layer of anti-rust oil and storing in a sealed container with desiccants is essential. Advanced rust can significantly degrade their value. For any material, the use of abrasive or metal polishes is strictly prohibited as it can harm the patina and drastically decrease the coin's value. If cleaning is necessary, gently wiping with a dry soft cloth is advisable. Refer to [Guide to Coin Storage and Maintenance](/guide/storage) for detailed methods to protect valuable collections. ## Starting a Collection and Market Value Tōshi Monsen, with its affordable range, is one of the best coin types to start collecting cash coins. Standard coins can be easily obtained for 100 to 500 yen, allowing exploration of material differences and wave variations. Due to their large size and aesthetic appeal, they offer a high level of satisfaction as a first old coin. A recommended first step in collecting is obtaining one coin each of copper, brass, and iron to feel their differences firsthand. Subsequently, seeking coins with clear wave designs or distinctive scripts enriches the collecting experience. Brass coins in good condition are particularly popular and can be valued at several thousand yen based on their condition. As an investment, it's challenging to expect significant appreciation in common circulation coins, but rare mother coins, special year coins from initial minting, or coins with very unusual scripts can have values ranging from tens of thousands to more. Starting a collection of Tōshi Monsen through reliable sources is crucial as advised in [Guide to Coin Acquisition and Purchasing Methods](/coinpedia/basics-008-shotai).