After the Great Kanto Earthquake deals a heavy blow to the telephone systems of Tokyo and Yokohama, it is quickly decided that the rebuilding effort will rely on step-by-step type automated switching equipment. Work begins in February of Taisho 14 (1925) and by the following January, the first automated exchange in Japan is installed in the Kyobashi Branch in Tokyo. By March of the same year the Yokohama Main Office and Choja-Machi Branch are provided with automation .