海部俊樹
The Emperor's death ended the Shōwa era. On the same day a new era began: the Heisei era, effective at midnight the following day. From 7 January until 31 January, the Emperor's formal appellation was "Departed Emperor." His definitive posthumous name, Shōwa Tennō, was determined on 13 January and formally released on 31 January by Toshiki Kaifu, the prime minister.