Japan has a complex monetary history that has evolved over centuries. During the feudal period (1603-1868), the ryō was the primary monetary unit. The Meiji era (1868-1912) marked the introduction of the yen, replacing the ryō, as part of Japan's modernization. The interwar period saw economic challenges, and post-World War II witnessed a monetary reform in 1946 with the reintroduction of the yen. Since then, the Japanese yen has remained the national currency, playing a key role in the global economy, with the Bank of Japan influencing the country's monetary policy.