Title: Japanese currency
Content:  Before the 7th-8th centuries AD, Japan used commodity money for trading. This generally consisted of material that was compact and easily transportable and had a widely recognized value. Commodity money was a great improvement over simple barter, in which commodities were simply exchanged against others. Ideally, commodity money had to be widely accepted, easily portable and storable, and easily combined and divided in order to correspond to different values. The main items of commodity money in Japan were arrowheads, rice grains and gold powder. This contrasted somewhat with countries like China, where one of the most important items of commodity money came from the southern seas: shells. Since then however, the shell has become a symbol for money in many Chinese and Japanese ideograms.
Title: Japanese yen
Content:  The yen (円) is the official currency of Japan. It is the third most traded currency in the foreign exchange market, after the United States dollar and the Euro. It is also widely used as a third reserve currency after the United States dollar and the Euro. The concept of the yen was a component of the late-19th century Meiji government's modernization program of Japan's economy, which postulated the pursuit of a uniform currency throughout the country, modeled after the European decimal currency system. Before the Meiji Restoration, Japan's feudal fiefs all issued their own money, hansatsu, in an array of incompatible 
Title: Japanese mon (currency)
Content:   The mon was the currency of Japan from the Muromachi period in 1336 until the early Meiji period in 1870. It co-circulated with the new sen until 1891. The Kanji for mon is 文 and the character for currency was widely used in the Chinese-character cultural sphere, e.g. Chinese wen, Korean mun, Vietnamese văn. Throughout Japanese history, there were many different styles of currency of many shapes, styles, designs, sizes and materials, including gold, silver, bronze, etc. Coins denominated in mon were cast in copper or iron and circulated alongside silver and gold ingots denominated in shu, bu and ryō, with 4000 mon = 16 shu = 4 bu = 1 ryo. In 1869, due to depreciation against gold, the new fixing officially was set for 1 ryo/yen = equal to 
Title: Financial services in Japan
Content:  The currency of Japan is Japanese Yen, and the Japanese Yen to European pound exchange rate is the most popular. JPY is the code of the currency and ¥ is the symbol of the Japanese Yen. The minor unit of Japanese Yen is 1/100 which is called a Sen. The central bank rate is -0.10. JPY's inflation rate is 0.50% presently (subject to change as the market is constantly changing). The currency denominations in coins are ¥1, ¥5, ¥10, ¥50, ¥100, ¥500 and the notes are ¥1000, ¥5000, ¥10000 and ¥2000 which is rarely used. Japan's central bank is the Bank of Japan. 
Title: List of motifs on banknotes
Content:  The official currency of Japan is the Japanese yen (JPY). The motifs used are: 1984 Series (Series D): 2000 Special (Series D): 2004 Series (Series E):
Title: Japanese currency
Content:  Following 1868, a new currency system based on the Japanese yen was progressively established along Western lines, which has remained Japan's currency system to this day. Immediately after the Meiji Restoration in 1868, previous gold, silver and copper coins, as well as feudal notes, continued to circulate, leading to great confusion. In 1868, the government also issued coins and gold-convertible paper money, called  (太政官札), denominated in Ryō, an old unit from the Edo period, and private banks called Kawase Kaisha were allowed to issue their own currency as well. Complexity, widespread counterfeiting of gold coins and feudal notes led to widespread confusion.
Title: Imperial Japanese Army
Content:  the military yen—or "Japanese invasion money", as it came to be known by the locals—was the only legal tender in circulation. The Japanese authorities seized or ordered surrendered all other bank notes in territories under their occupation and provided compensation at an "exchange rate" as they saw fit, in the form of JMYs. This had the effect of affording Japanese soldiers in many occupied territories a higher degree of return for their low pay than they otherwise would have received. However, at the end of the war, the Imperial Japanese ministry of finance cancelled all military bank notes, rendering the military yen worthless.
Title: Japanese military currency (1937–1945)
Content:  Japanese military currency (Chinese and Japanese: 日本軍用手票, also 日本軍票 in short) was money issued to the soldiers of the Imperial Japanese Armed Forces as a salary. The military yen reached its peak during the Pacific War period, when the Japanese government excessively issued it to all of its occupied territories. In Hong Kong, the military yen was forced upon the local population as the sole official currency of the territory. Since the military yen was not backed by gold, and did not have a specific place of issuance, the military yen could not be exchanged for the Japanese yen. Forcing local populations to use the military yen officially was one of the ways the Japanese government could dominate the local economies.
Title: Japanese currency
Content:  The earliest coins to reach Japan were Chinese Ban Liang and Wu Zhu coins, as well as the coins produced by Wang Mang during the first centuries of the first millennium AD; these coins have been excavated all over Japan, but as Japan's economy was not sufficiently developed at the time, these coins were more likely to be used as precious objects rather than a means of exchange; rice and cloth served as the main currencies of Japan at the time. The first coins produced in Japan are called the Mumonginsen (無文銀銭, or 'silver coins without inscription') and the copper alloy Fuhonsen (富本銭, coins made from an alloy of copper, lead and tin) which were all introduced in the late seventh century. These currencies (alongside other reforms) were based on the Chinese system and were therefore based on the Chinese units of measurement. In modern times the usage of Fuhonsen has often been interpreted as charms rather than currency, but it has recently been discovered that these copper coins were in fact the first government-made coinage of Japan.
Title: Japanese currency
Content:  Through the New Currency Act of 1871, Japan adopted the gold standard along international lines, with 1 yen corresponding to 1.5g of pure gold. The Meiji government issued new notes, called Meiji Tsūhōsatsu (明治通宝札), in 1872, which were printed in Germany. Silver coins were also issued for trade with Asian countries who favoured silver as a currency, thus establishing a de facto gold-silver standard.

Question: what do they call money in japan?
Answer: Japanese yen.