In April 1923, Seiji Kato (first president of Okasan Securities Co., Ltd.) founded the Okasan Company in Kyoguchi-machi, Tsu City, Mie Prefecture. The company was reorganized and incorporated on August 25, 1944, when it became Okasan Securities Co., Ltd. In October 2003, Okasan Holdings, Inc., was renamed in line with the transformation of the company into the holding company system. In October 2008, the company name was changed to Okasan Securities Group Inc.