History shows us the following explanation.

Table for Composition and Weight of the Newly Produced Coin under the New Coinage Act in 1871 stipulated “the Obverse side to be borne Ryumon or Rising Dragon image to symbolize the Emperor”.

However in August, 1873 under the Cabinet Ordinance, new 2 Sen copper coins together with other copper coins were stipulated to bear the Ryumon or Rising Dragon image on the reverse side. Furthermore under the Cabinet Ordinace in 1874, 1 Yen silver coin (trade dollar) was also stipulated to be borne the image on the reverse side. Accordingly no unity was found among coinage.

Therefore in June, 1875 at the time of renaming the New Coinage Act to Coinage Act Ryumon was stipulated to be borne on obverse side of coins.

Cabinet Order of Coinage Specifications stipulated under the Coinage Law in 1897, did not have any stipulations regarding both sides of the coins. However, the side with the Chrysanthemum Crest image is called obverse and this practice had long been effective.

After World War II, the Chrysanthemum crest pattern was not used on the surface so that no one could specify the obverse and reverse of coin.

As all the coins manufactured after 1897 in practice bore the year inscription on the reverse side, so the side with year mark has commonly been called reverse and logically the other side has been called obverse.

In working practice the side borne dated- mark has been called reverse.

Before Meiji era (1868) there were oblong and square shaped coins. All coins were produced in round shaped after that era. In 1869 the government decided to adopt OKUMA's opinion of encouraging the rounded coin production.

His opinions were:

1. Rounded-coins were handled easier than square coins.
2. More resistant against erosion.

The Yen was stipulated under the New Coinage Act in 1871. There are various reasonable explanations of the origin. Complete documentation is unavailable, however, roughly there may be two kinds of explanations.

1. The shape of coin was converted from square into round. In Japan we pronounce Yen for roundness.
2. At the establishment of the Mint the manufacturing machines were imported from Hong Kong Royal Mint, U .K., which produced silver dollar coins with denomination inscription of 1 Yen () (Yuan in Chinese, Yen in Japanese) on the surface.

Supplementary reason for adopting Yen may be as follows:

1. If ""is described as “En”, it is difficult for foreigners to pronounce as Japanese do.
   
2. As in China "", the unit of paper-note, was pronounced "Yuan", so the Japanese "" described as "Yen". (At that time "Edo" was described as "Yedo").
3. Since in French "En" means "In", in Dutch "En" means "And", "En" was avoided for the spelling mistakes and complexity.

Among the coins withdrawn by the Bank of Japan, unusable coins such as eroded, deformed and discolored coins are forwarded to the Mint, manufacturer of these coins. When they accumulated, the Mint remelts them in accordance with the material and reuses for coinage.

Originally the coin was milled in order to

1. prevent scalping the edge of precious gold and silver coins.
2. indicate the highest valued denomination coin at that time.

Now it is done in order to

1. identify the specific coin easily (distinguish the specific coin from others).
2. prevent the counterfeiting.

Japan Mint manufactures coins. National Printing Bureau produces banknotes.
The government issues coins but the banknotes are issued by the Bank of Japan, an separate body of government.
Japan Mint engages in manufacturing coins, production of industrial metal art objects, certification of fineness of the metal ores and sales of commemorative coins etc.
National Printing Bureau engages in producing banknotes, postal stamps, postal cards, seals, government bonds and bonds etc.

According to the Japanese Currency Law, maximum pieces of up to 20 coins of the same denomination can be used as legal tender. Rejection of the acceptance under 20 pieces of the same denomination is prohibited. In case of over 20 pieces you can reject accepting the coins in daily transactions.
Coins are useful in small transactions. Transaction-wise it is inconvenient for you to accept and to store large amounts of small coins.

Commemorative coins are issued to mark the national celebrations and commemorative events under the authorization of the Cabinet.

Precisely speaking "The Annual Trial of the Pyx" , weight test of the coins, is held in the Osaka Head Office to ensure and check whether the weight of the coin is within the range of stipulated allowance. Mr.INOUE, the Finance Minister of that time held the first ceremony in 1872. Since then the test has been executed annually except in 1912.

Yes, there are twelve coins as shown below.

1. 1 sen aluminum coin (issued in 1941)
2. 1 sen ceramic coin (produced in 1945, not issued)
3. The Tokyo Olympics commemorative 1000 yen silver coin (issued in 1964).
4. The Japan World Exposition 100 yen cupronickel coin (issued in 1970)
5. The 10th year of the Emperor on the throne 500 yen cupronickel coin (issued in 1999)
6. The International Skills Festival for All, Japan 2007 1000 yen silver coin (issued in 2007)
7. The 67th Annual Meetings of the International Monetary Fund and the World Bank Group 1000 yen silver coin (issued in 2012)
8. The 60th Anniversary of Enforcement of the Local Autonomy Law (Shizuoka) 1000 yen silver coin (issued in 2013)
9. The 60th Anniversary of Enforcement of the Local Autonomy Law (Shizuoka) 500 yen bicolor clad coin (issued in 2013)
10. The 60th Anniversary of Enforcement of the Local Autonomy Law (Yamanashi) 1000 yen silver coin (issued in 2013)
11. The 60th Anniversary of Enforcement of the Local Autonomy Law (Yamanashi) 500 yen bicolor clad coin (issued in 2013)
12. The 50th Anniversary of the Shinkansen 1000 yen silver coin(issued in 2014)

"Proof Coin" originally means a coin which is especially produced for comparison with circulating coins (as it were "Standard Coin"). Generally speaking, it is a brilliantly polished numismatic coin. The proof coin is carefully produced with special techniques.
For example, the surfaces of coining dies are polished with much care and coins are stamped more than once in order to make the relief-work deeper and clearer. Proof coins produced in our mint and sold in Japan, have a mirror like luster in the hollow area of the surface but have no luster in the highly raised area of the surface. The upper part is distinguishable from the lower part.

The premium coin is a commemorative coin, made of precious metal, and is sold at a price above the production cost and the surface denomination.
The first one issued in Japan was the commemorative gold coin of the Winter Olympic Games in Nagano.

Currently we produce 6 kinds of circulating coins from 1 yen to 500 yen coins.

The designs generally represent typical Japanese culture and everyday life in harmony with the nature such as plants (chrysanthemum, cherry blossoms and paulownia flowers).
Furthermore, they signify good old Japanese life based on rice planting and cropping (land of rice).
Natural beauty such as Mt.Fuji and cultural properties such as famous temples and shrines are also depicted.

The Mint examines the fineness of precious metal wares and certifies the fineness of such wares by stamping the following marks on all wares that pass this examination. Such a mark is commonly called a hallmark.

Moving Picture

Fineness Certification of Precious Metal Wares