The cultured pearl industry in Japan developed rapidly, both in expanding pearl fishery fields from Mie Prefecture to Nagasaki Prefecture and along the Seto Inland Sea, and in expanding trade market in the world. Although during the Meiji era (〜1912), Mikimoto monopolizd the cultured pearl industry, strong competations against Mikimoto's monopoly appeared gradually in the Taisho era. In the Showa era, two groups started to co-operate and self-controlled the production. It seems that the cultured pearl industry in Japan was developing in harmony during these days, in spite of the fact that the production increased in a reciprocal relation with the decrease in sales and prices. However, outbreak of the 2nd World War stopped this harmonic development and gave the most severe damage to the Japanese cultured pearl industry. The production of cultured pearl was entirely forced to cease during the war.
