This article reviews the top phosphoric acid manufacturers and suppliers in Japan, including Nippon Phosphoric Acid, Shimane Phosphate, Mitsui & Co., Rin Kagaku Kogyo, and RASA Industries. It covers their products, applications, quality standards, and innovation efforts, highlighting Japan’s role as a global leader in phosphoric acid production. The article also discusses OEM services, industry challenges, and future trends, providing a comprehensive overview of the Japanese phosphoric acid market.