Emperor of Japan
Currently, the Emperor of Japan is the only head of state in the world with the English title of "Emperor". The Imperial House of Japan is the oldest continuing monarchical house in the world. The historical origins of the Emperors lie in the late Kofun period of the 3rd–7th centuries AD, but according to the traditional account of the "Kojiki" (finished 712) and "Nihon Shoki" (finished 720), Japan was founded in 660 BC by Emperor Jimmu, who was said to be a direct descendant of the sun-goddess Amaterasu. The current Emperor is Akihito. He acceded to the Chrysanthemum Throne upon the death of his father, Emperor Shōwa (Hirohito), in 1989. The Japanese government announced in December 2017 that Akihito will abdicate on 30 April 2019.
Line of succession to the Japanese throne
Before September 2006, there was a potential succession crisis since no male child had been born into the imperial family since Prince Akishino in 1965. Following the birth of Princess Aiko, there was significant public debate about amending the Imperial House Law to allow female descendants of an emperor and their descendants to succeed to the throne. In January 2005, Prime Minister Junichiro Koizumi appointed a special panel of judges, university professors, and civil servants to study changes to the Imperial House Law and to make recommendations to the government.