After the 1980s, Choi started managing real estate business and operating kindergartens. In 1983, she acquired 45-pyong (about 149 square meters) of land in Yeoksam-dong, Seoul; in September 1985, she acquired 108-pyong (about246 square meters) of land in Sinsa-dong and built a 4-story building. A kindergarten used to be operated in this building. In July 1988, she bought a 200-pyong (about 661 square meters) space of land in Sinsa-dong under a joint-contract with someone else  Later, she bought back the joint shares and became the sole owner of the property. From 1992 to 1996, Choi established and operated Jubel GmbH jointly with Chung Yoon-hoi. In July 2003, a building (referred to as M building) with 7 floors above ground and 2 floors underground was constructed with Choi’s investment. Chung Yoon-hoi’s company was a tenant in this building. In February 2008, Choi sold the kindergarten building to a savings bank. In 1989, Choi translated a child-care instruction book called “How To Hold Your Children’s Habit Upright