NAIGAI Co., Ltd. engages in the manufacture, sale, import, and export of textile products such as socks, hosiery, and pantyhose. It operates through the Wholesale Business and Retail Business segments. The Wholesale Business segment deals with the production, import, and export of socks and legwear. The Retail Business segment manages the operation of the store Happy Socks. It also handles the sale of mail-order products such as textile and leather products through the Internet through its subsidiary. The company was founded by Koichi Yoda and Masakazu Kobayashi in August 1920 and is headquartered in Tokyo, Japan.