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.
Ise Grand Shrine
During the Empire of Japan and the establishment of State Shinto, the position of chief priest of the Ise Shrine was fulfilled by the reigning emperor and the Meiji, Taisho and Shōwa Emperors all played the role of chief priest during their reigns.
Since the disestablishment of State Shinto during the Occupation of Japan, the offices of chief priest and most sacred priestess have been held by former members of the imperial family or their descendants. The current chief priest of the shrine is Takatsukasa Naotake, adoptive son of Takatsukasa Kazuko. He succeeded Kitashirakawa Michihisa, a great-grandson of the Meiji Emperor, in 2007. Kitashirakawa Michihisa succeeded his cousin Kuni Kuniaki, the eldest son of former Prince Kuni Asaakira (brother of Empress Kōjun), in 2001. Kitashirakawa's grandmother, Kitashirakawa Fusako, the seventh daughter of the Meiji Emperor, served as most sacred priestess of the Ise Shrine from 1947 until her death in 1974. She was succeeded in that post by Takatsukasa Kazuko, third daughter of the Emperor Shōwa, who held the post until ill health forced her retirement in 1988. Takatsukasa Kazuko was succeeded by her younger sister, Ikeda Atsuko. In 2012, Ikeda was joined by her niece Kuroda Sayako, sole daughter of reigning Emperor Akihito, to serve as a high priestess under her. On 19 June 2017, Kuroda officially replaced her aunt as supreme priestess.