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.
List of rulers of Japan
The rulers of Japan have been its Emperors, whether effectively or nominally, for its entire recorded history. These include the ancient legendary emperors, the attested but undated emperors of the Yamato period (early fifth to early 6th centuries), and the clearly dated emperors of 539 to the present. Political power was held in various eras by regents and "shōguns", and since 1946 has been exercised exclusively by the Prime Minister as leader of a representative government.