The Showa period ("period of enlightened peace") was the time in Japanese history when Emperor Hirohito reigned over the country, from December 25, 1926 to January 7, 1989. It was the longest reign of all Japanese emperors.

This was invented by fans, and was accepted into the mainstream to differentiate the Honda-Tsuburaya era (1954-1975) and the later films, which are classified under the "Heisei Period", the current era name in Japan. The Heisei era started on January 8, 1989. In 1989, Akihito, the current emperor of Japan succeeded to the throne, after the death of his father, Hirohito, the Showa Emperor. Thus that year corresponds to Heisei 1. 2006 is Heisei 18.
August Ragone
kaijupro@yahoo.com