The Emperor of Japan is the head of the Imperial Family and the head of state of Japan. Under the 1947 constitution, he is defined as "the symbol of the State and of the unity of the people." Historically, he is also the highest authority of the Shinto religion. In Japanese, the emperor is called Tennō (天皇), literally "heavenly sovereign". In English, the use of the term Mikado (帝 or 御門) for the emperor was once common, but is now considered obsolete.
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 Naruhito. He acceded to the Chrysanthemum Throne upon the abdication of his father, the now-Emperor Emeritus Akihito on 1 May 2019 at 00:00 local time (15:00 UTC).
The role of the Emperor of Japan has historically alternated between a largely ceremonial symbolic role and that of an actual imperial ruler. Since the establishment of the first shogunate in 1199, the emperors have rarely taken on a role as supreme battlefield commander, unlike many Western monarchs. Japanese emperors have nearly always been controlled by external political forces, to varying degrees. For example, between 1192 and 1867, the shōguns, or their shikken regents in Kamakura (1203–1333), were the de facto rulers of Japan, although they were nominally appointed by the emperor. After the Meiji Restoration in 1867, the emperor was the embodiment of all sovereign power in the realm, as enshrined in the Meiji Constitution of 1889. Since the enactment of the 1947 Constitution, the role of emperor has been to act as a ceremonial head of state without even nominal political powers.
Since the mid-nineteenth century, the Imperial Palace has been called Kyūjō (宮城), later Kōkyo (皇居), and is on the former site of Edo Castle in the heart of Tokyo (the current capital of Japan). Earlier, emperors resided in Kyoto (the ancient capital) for nearly eleven centuries. The Emperor's Birthday (currently 23 February) is a national holiday.
Unlike most constitutional monarchs, the Emperor is not the nominal chief executive. Article 65 explicitly vests executive power in the Cabinet, of which the Prime Minister is the leader. The Emperor is also not the commander-in-chief of the Japan Self-Defense Forces. The Japan Self-Defense Forces Act of 1954 also explicitly vests this role with the Prime Minister.
The Emperor's powers are limited only to important ceremonial functions. Article 4 of the Constitution stipulates that the Emperor "shall perform only such acts in matters of state as are provided for in the Constitution and he shall not have powers related to government." It also stipulates that "the advice and approval of the Cabinet shall be required for all acts of the Emperor in matters of state" (Article 3). Article 4 also states that these duties can be delegated by the Emperor as provided for by law.
While the Emperor formally appoints the Prime Minister to office, Article 6 of the Constitution requires him to appoint the candidate "as designated by the Diet", without giving the Emperor the right to decline appointment.
Article 6 of the Constitution delegates the Emperor the following ceremonial roles:
- Appointment of the Prime Minister as designated by the Diet.
- Appointment of the Chief Justice of the Supreme Court as designated by the Cabinet.
The Emperor's other duties are laid down in article 7 of the Constitution, where it is stated that "the Emperor, with the advice and approval of the Cabinet, shall perform the following acts in matters of state on behalf of the people." In practice, all of these duties are exercised only in accordance with the binding instructions of the Cabinet:
- Promulgation of amendments of the constitution, laws, cabinet orders, and treaties.
- Convocation of the Diet.
- Dissolution of the House of Representatives.
- Proclamation of general election of members of the Diet.
- Attestation of the appointment and dismissal of Ministers of State and other officials as provided for by law, and of full powers and credentials of Ambassadors and Ministers.
- Attestation of general and special amnesty, commutation of punishment, reprieve, and restoration of rights.
- Awarding of honors.
- Attestation of instruments of ratification and other diplomatic documents as provided for by law.
- Receiving foreign ambassadors and ministers.
- Performance of ceremonial functions.
Regular ceremonies of the Emperor with a constitutional basis are the Imperial Investitures (Shinninshiki) in the Tokyo Imperial Palace and the Speech from the Throne ceremony in the House of Councillors in the National Diet Building. The latter ceremony opens ordinary and extra sessions of the Diet. Ordinary sessions are opened each January and also after new elections to the House of Representatives. Extra sessions usually convene in the autumn and are opened then.