Emperor of Japan
The current Emperor on the throne is typically referred to as "Tennō Heika" (, "His (Imperial) Majesty the Emperor"), "Kinjō Heika" (, "His Current Majesty") or simply "Tennō", when speaking Japanese. The current Emperor will be renamed "Daijō Tennō" (, Retired Emperor), often shortened to "Jōkō" (), upon his planned retirement on 30 April 2019, and renamed "Heisei Tennō" () after his death and will then be referred to exclusively by that name in Japanese. In Japanese culture, it is considered a major faux pas to refer to a living Emperor by his posthumous name, although the posthumous name is the same as the era, which is used in official documents.
Emperor of Japan
Article 2 of the Constitution of Japan, promulgated in 1947 by influence of the U.S. occupation administration, provides that "The Imperial Throne shall be dynastic and succeeded to in accordance with the Imperial Household Law passed by the Diet." The Imperial Household Law of 1947, enacted by the ninety-second and last session of the Imperial Diet, retained the exclusion on female dynasts found in the 1889 law. The government of Prime Minister Yoshida Shigeru hastily cobbled together the legislation to bring the Imperial Household in compliance with the American-written Constitution of Japan that went into effect in May 1947. In an effort to control the size of the imperial family, the law stipulates that only legitimate male descendants in the male line can be dynasts; that imperial princesses lose their status as Imperial Family members if they marry outside the Imperial Family; and that the Emperor and other members of the Imperial Family may not adopt children. It also prevented branches, other than the branch descending from Taishō, from being imperial princes any longer.