coin in 1959. These were replaced in 1967 by the current cupro-nickel 100 yen along with a smaller 50 yen. In 1982, the first cupronickel 500 yen coin was introduced. Alongside with the 5 Swiss franc coin, the 500 yen coin is one of the highest-valued coin to be used regularly in the world, with value of US$4.5 . Because of its high face value, the 500 yen coin has been a favorite target for counterfeiters, resulting in the issuance in 2000 of the second nickel-brass 500 yen coin with added security features. Continued counterfeiting of the latter resulted in the issuance in 2021 of the third bi-metallic 500 yen coin with more improvements in security features. The observe side of all coins shows the coin's value in kanji as well as the country name (through 1945, ; after 1945, (except for the current 5-yen coin with the country name on the reverse). The reverse side of all coins shows the year of mintage, which is not shown in Gregorian calendar years, but instead in the regnal year of the current emperor's reign. For reference: Coins minted in 1900 bear the year 明治 (Meiji) 33, the 33rd year of Emperor Meiji's reign Coins minted in 1920 bear the year 大正 (Taisho) 9, the 9th year of Emperor Taisho's reign Coins minted in 1980 bear the year 昭和 (Showa) 55, the 55th year of Emperor Hirohito's reign Coins minted in 2000 bear the year 平成 (Heisei) 12, the 12th year of Emperor Akihito's reign Coins minted in 2020 bear the year 令和 (Reiwa) 2, the 2nd year of Emperor Naruhito's reign Due to the great differences in style, size, weight and the pattern present on the edge of the coin they are easy for people with visual impairments to tell apart from one another. Commemorative coins have been minted on various occasions in base metal, silver and gold. The first of these were silver ¥100 and ¥1,000 Summer Olympic coins issued for the 1964 games. The largest issuance by denomination and total face value were 10 million gold coins of ¥100,000 denomination for the 60th anniversary of reign of the Shōwa Emperor in 1986, totalling ¥1 trillion and utilizing 200,000 kg fine gold. ¥500 commemorative coins have been regularly issued since 1985. In 2008 commemorative ¥500 and ¥1,000 coins were issued featuring Japan's 47 prefectures. Even though all commemorative coins can