Prescription Kampo preparations are Tsumura's core business sector, and the company elucidates Kampo pharmacology scientifically to encourage physicians to prescribe Kampo preparations. Tsumura also conducts research on chemical pharmaceuticals, focusing on active ingredients from medicinal herbs for treating renal, immunological and allergenic problems. Outside Japan, Tsumura stepped up its activity in 2001 in Asia and North America. Sales of Tsumura Kampo preparations began in the over-the-counter market in the Republic of Korea. A newly established joint venture in China is preparing to produce Kampo extracts for export to Japan and Kampo preparations for marketing locally. Tsumura also is active in purchasing medicinal herbs and in supporting their cultivation in China and other Asian nations. The company continues to market toiletries in several nations, and it recently expanded its sales channels for toiletries and other household goods in the United States.