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
Japanese monarchs were given their official title by the Chinese emperor. The new Japanese monarch after coming into power would send a representative to China and receive the anointment. They would receive their official title on several golden plates of several meters tall. Since the Japanese monarchs changed their title to 天皇 (Heavenly Emperor) in 607, the Chinese emperor refused to anoint the Japanese king, thus, ending relations with Japan for the next few hundred years. Although the Japanese emperors used Chinese imperial titles, rarely was the Chinese-style "Son of Heaven" used. In the Japanese language, the word "tennō" is restricted to Japan's own monarch; "kōtei" (皇帝) is used for foreign emperors. Historically, retired emperors often kept power over a child-emperor as de facto regent. For a long time, a "shōgun" (formally the imperial generalissimo, but made hereditary) or an imperial regent wielded actual political power. In fact, through much of Japanese history, the emperor has been little more than a figurehead.