well, "Japanese coin" can be called "nihon no KOIN" (caps for katakana, lowercase for hiragana or kanji). However, the Japanese unit of currency involves coins which hold 5, 10, 50, 100, and 500 yen (en in Japanese) in value.
Chat with our AI personalities
On one side of the Japanese coins currently in circulation is written the value (in yen) of the coin and the year the coin was made. Except for the 5-yen coin, the value is written in Arabic numerals. On all coins the year is written in the Japanese style, with the name of the then-current Emperor's reign name and the year of the reign (e.g., 平成十二年 for Heisei Year 2, or the second year of the reign of the [as of mid-2012] current Emperor, year 2 being 1990). On the 5-yen coin, the value of the coin is written in the Chinese character for "five," viz. 五).
On the other side of the coin is written the value of the coin in Chinese characters and 日本国, or something to the effect of "Japan."
The ¥500 yen coin made until 1989 additionally had "Nippon Ginkou" (or "Ginko") (i.e., "Bank of Japan") etched in Roman letters along the edge. The new ¥500 coin has instead of the Roman letters a series of parallel scores.