In the world of Kokuryu, the world's sole currency, the Zeran, was introduced after the economic crash of 2008. The EarthBank established the Zeran as a sound digital and physical currency (SDPC) and features bank notes made out of real metal foil instead of paper and digits to prevent counterfeiting and inflation. (Both of which are white-collar crimes punishable by death). The 50 Zeran Banknote is made out of copper and zinc alloy foil and features the lion as its symbol.