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.
Government of Japan
The Emperor is known to hold the nominal ceremonial authority. For example, the Emperor is the only person that has the authority to appoint the Prime Minister, even though the Diet has the power to designate the person fitted for the position. One such example can be prominently seen in the 2009 Dissolution of the House of Representatives. The House was expected to be dissolved on the advice of the Prime Minister, but was temporarily unable to do so for the next general election, as both the Emperor and Empress were visiting Canada.