Kohsai Co.,Ltd. engages in the jewelry business in Japan. The company manufactures and sells precious metal accessories and jewelry parts. Its products include clasps, rings, and earrings, as well as products for men. The company was formerly known as Kosaikogei Co.,Ltd. and changed its name to Kohsai Co.,Ltd. in August 2017. The company was incorporated in 1967 and is headquartered in Kai, Japan. Kohsai Co.,Ltd. is a subsidiary of Estio Co., Ltd.