On August 1, 1952, the Ministry of Electrical Communications is closed, and the Japan Telephone and Telegraph Corporation is born. With this step in development, Japan's telegraph and telephone communication industry sheds the regulatory shell that has encapsulated it since its founding 63 years earlier, and becomes an autonomous enterprise in which public and private interests are merged. At about the same time, the first female section managers are appointed, an important achievement in the advancement of women in society. The following year marks the start of the great revision of exchange numbers in Tokyo.