- Our Products We have a sales company (JDA) and a manufacturing factory (KOTOBUKI Factory Co., Ltd.) within our JDA group. This business structure allows us to quickly reflect our customers' needs and requests on our products. We use high-quality "Made in Japan" materials and manufacture in our factory in Nara, Japan. Under the strict quality inspection system, we receive the highest rating in terms of quality and technical capability within the filter industry. We provide the contents of ...