The period after the war, starting in 1945, saw Japan's money system changing greatly, with the country dealing with high inflation and needing to fix its economy.
This situation led to constant changes in the coins, making their materials, sizes, and designs different very often.
These fast and frequent changes are the main reason some coins, made only for short periods, are now very rare, leading to high value.
And for many collectors, it may be too difficult to at least recognize the year of minting on such tokens without the help of the coin-identifier.com.
Mintage: When a coin's making time was very short, the total number produced was usually low, directly causing high rarity and leading to high prices in the collecting market.
Money and Material Issues Causing Short Production Times
The short time for making coins in post-war Japan happened because of three main groups of reasons, all leading to sudden changes and low production numbers.
Economic Instability and Price Rises (1945–1955)
Right after the war, the rise in prices was very fast, meaning the cost of the metal used to make the coins was often higher than the coin's face value.
Adding a hole to the middle of some coins, like the 5 and 50 Yen, was done to save metal.
But when the price of metal went down again, or when new ways allowed coins to be made thinner, the design quickly changed, resulting in very short periods for making the older coin types.
Because strategic metals like copper and nickel were hard to get and cost a lot to bring in, the coin factory was forced to change the metal alloys often.
For example, changing from aluminum to brass, and then to a copper-nickel mix, each change created a new type of coin with a limited production time.
Changes in Rules and Design (1955–1988)
As the economy became more stable, the government brought in new rules, setting the standards for the coins. Each new rule caused the old coins to stop being made.
For example, one type of Japanese writing was used on coins in 1948, with a different type of writing being introduced in 1949.
The 1948 coins, having the old writing, were made for a short time, now becoming a collector's item because of their quick replacement.
The Changing of Emperors
In Japan, the year on the coin shows the year of the current Emperor's rule. When an Emperor dies and a new one starts, there is a very short time when production must change.
Coins made in the last year of one Emperor, or in the first year of the new one, have a very low number made, because the factory cannot make enough coins before the date and design officially changes, making these coins some of the most expensive.
Examples of Rare Coins with Short Production Times
Denomination | Year | Production Period | Rarity Status |
5 Yen | Showa 24 (1949) | 1 Year | High |
5 Yen | Showa 32 (1957) | 1 Year | Medium-High |
50 Yen | Showa 30 (1955) | 1 Year | Very Rare |
100 Yen | Heisei 12 (2000) | A Few Weeks | Medium-High |
500 Yen | Heisei 1 (1989) | 1 Year | High |
50 Yen Showa 30 (1955) Coin
This coin was issued in 1955 and does not have a hole in the middle.
People found it too similar to a 100 yen coin due to its similar color and size, which caused a lot of confusion when using it.
The government made a fast decision to change the design, adding a hole.
As a result, the 1955 coin without a hole was made for less than one full year, immediately making it one of the rarest and most expensive coins for collectors, having a very low total number made, and being quickly taken out of circulation.
5 Yen Showa 24 (1949) Coin
In this situation, the rarity comes from a mistake. The factory used an old Japanese character for the word "Japan" on the back of the coin this year, this mistake being quickly seen and fixed the following year.
Even if you feel like a professional in distinguishing the features of each Japanese coin, it would not be superfluous to check yourself via a coin identification so as not to get confused in your own collection.
The 1949 coins, carrying the mistaken character, have a low production number and are highly wanted by collectors because they are unique.
How Rarity Affects Cost
The curve showing the price of collectible Japanese coins does not go straight up, but jumps very sharply when the coin is extremely rare, with this highest rarity usually happening with the shortest production time.
Starting Level
Coins made for many years and in huge numbers, such as the 10 Yen from the Showa 1960s, have a low value for collectors, with their price in the market being almost the same as their face value, keeping the price curve almost flat here.
Medium Rarity
These are coins made during times of money or machine changes, lasting for two to three years. They have a medium total number made, and their price is higher than the face value but remains easy for many collectors to afford, causing the price curve to start rising gently.
Short Production Time
These coins were made for only one year or even just a few months, like the 50 Yen Showa 30 coin.
Because very few copies exist, these coins are owned by a small number of collectors.
High demand and very low supply cause the price to jump sharply, with the coin's cost becoming maybe thousands of times more than its face value.
The simple rule of scarcity shows that the shorter the production time was, the fewer coins are left, and the higher their price will be, this simple fact making the top part of the price curve very steep.
The Coin's Grade
A short production time decides the coin’s basic rarity, but the coin’s condition, or its grade, acts as a multiplier, greatly increasing the final cost.
Used Coins
Coins that were used in daily shopping have wear and marks.
Even rare coins made for a short time will cost much less if their condition is poor.
Perfect Coins
Perfect coins that have never been used, showing no signs of any contact except from the factory, cost the most.
If a coin with a short production time, giving it basic rarity, is also in perfect condition, its price goes up very sharply, but to be sure, check the token via a coin scanner.
For example, a rare 50 Yen 1955 coin in perfect condition might cost ten times more than the same coin that was used, showing that putting together "low total production + perfect condition" gives the maximum price.
Emperor Changes and Special Edition Coins
Showa 64 / Heisei 1 Transition (1989)
This is one of the clearest examples of a short production period. Emperor Showa died on January 7, 1989, and the new Emperor Heisei started his rule.
The year 1989 was divided into two: seven days belonged to Showa 64, which was the last year, and the rest of the time belonged to Heisei 1 — the first year.
Rarity of Showa 64: Coins marked with the date "Showa 64" were made only in those first seven days of January. The total number of these coins issued in this short time was extremely low, which automatically made them very rare
Rarity of Heisei 1: Despite the fact that Heisei 1 coins were produced for longer, they were still produced in fewer quantities than usual per year, and the mint needed time to replace machines and production tools
Commemorative Coins
These coins always have a short, fixed production time set by the government, being made for special times like the Olympics or big anniversaries.
Known Rarity: Unlike other coins, their rarity is known from the start because the total number made is announced publicly.
However, even among these special coins, some have a much lower total production than others, causing their price to climb fast on the valuation curve as well.
Conclusion
The price of post-war Japanese Yen coins in the collection market is decided not by their age, but mostly by the short and quickly stopped times they were made.
These short production periods were caused by these main factors:
Money problems needing fast changes in materials
New rules changing the coin's design and features
Unexpected events like the death of an Emperor and the changing of the era
Each of these short production times left behind a coin with a small total number made. The shorter this time was, the fewer coins are still here, the higher the rarity becomes, and the faster the coin moves up the collector's price curve.
