Kohsai Co.,Ltd. engages in the jewelry business in Japan. It offers jewelry and jewelry parts, which include earring parts and clasps, and forged rings. The company was formerly known as Kosaikogei Co.,Ltd. and changed its name to Kohsai Co.,Ltd. in August 2017. The company was founded in 1955 and is headquartered in Kai, Japan. Kohsai Co.,Ltd. operates as a subsidiary of Estio Co., Ltd.