Kohsai Co., Ltd. engages in the manufacture and sale of jewelry, metal accessories, and jewelry parts. The company also provides property, casualty, and life insurance services. Its products include bijou parts such as clasp, different earring clasps and catches, men's cuff, rings, pendants and others. The company was founded by Nobuo Fukasawa in October 1955 and is headquartered in Kai, Japan.