A public telephone service on Japan National Railways trains was temporarily postponed on September 30, 1964 (Showa 39), the day before the Tokaido Shinkansen started operation. However, the service was reintroduced on all Shinkansen trains on June 1, 1965 (Showa 40). Yokohama and Kyoto were added to the original participating exchanges (Tokyo, Nagoya and Osaka) when the service restarted.