The Imperial Household Law of 1947 (皇室典範, Kōshitsu Tenpan) is a Japanese law that governs the line of imperial succession, the membership of the imperial family, and several other matters pertaining to the administration of the Imperial Household.
In 2017, the National Diet changed the law to enable the Emperor Akihito to abdicate within three years. With this change, he abdicated on 30 April 2019 and was succeeded by his eldest son, Naruhito on 1 May 2019.
The emperor of Japan is the hereditary monarch and head of state of Japan. The emperor is defined by the Constitution of Japan as the symbol of the Japanese state and the unity of the Japanese people, his position deriving from "the will of the people with whom resides sovereign power". The Imperial Household Law governs the line of imperial succession. Pursuant to his constitutional role as a national symbol, and in accordance with rulings by the Supreme Court of Japan, the emperor is personally immune from prosecution. By virtue of his position as the head of the Imperial House, the emperor is also recognized as the head of the Shinto religion, which holds him to be the direct descendant of the sun goddess Amaterasu. According to tradition, the office of emperor was created in the 7th century BC, but the first historically verifiable emperors appear around the 5th or 6th centuries AD.
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 1192, the emperors of Japan 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. 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 1868, 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 relegated to that of a ceremonial head of state without even nominal political powers. The emperor is the head of the Japanese honors system, conferring orders, decorations, medals, and awards in the name of the state and on behalf of its people in accordance with the advice of the Cabinet.
The current line of succession to the Chrysanthemum Throne is based on the Imperial Household Law. At present, only direct male-line males are allowed to ascend the throne.
Sayako Kuroda (黒田 清子, Kuroda Sayako; born 18 April 1969), formerly Sayako, Princess Nori (紀宮清子内親王, Nori-no-miya Sayako Naishinnō), is the youngest child and only daughter of Emperor Emeritus Akihito and Empress Emerita Michiko, and the younger sister of the current Emperor of Japan, Naruhito. She is an imperial Shinto priestess of the Ise Grand Shrine, currently serving as the Supreme Priestess.
Kuroda held the appellation "Nori-no-miya" (Princess Nori), until her marriage to Yoshiki Kuroda on 15 November 2005. As a result of her marriage, she gave up her imperial title and left the Japanese imperial family, as required by the Article 12 of the Imperial Household Law, and received a payment of approximately US$1,000,000.
Aiko, Princess Toshi (敬宮愛子内親王, Toshi-no-miya Aiko Naishinnō; born 1 December 2001) is a member of the Imperial House of Japan. She is the only child of Emperor Naruhito and Empress Masako.
Following her birth, the ongoing Japanese imperial succession debate had resulted in some politicians holding a favorable view on rescinding agnatic primogeniture (male-only imperial succession) originally implemented in 1889 and retained by the Allies of World War II on the Constitution of Japan. However, once her uncle Crown Prince Fumihito had his son, Hisahito, in September 2006, Hisahito became second in the line of succession following his father. Aiko remains at present legally ineligible to inherit the throne and she cannot succeed her father, while debate about the possibility of having future empresses regnant continues.
The emperor of Japan is the hereditary monarch and head of state of Japan. The emperor is defined by the Constitution of Japan as the symbol of the Japanese state and the unity of the Japanese people, his position deriving from "the will of the people with whom resides sovereign power". The Imperial Household Law governs the line of imperial succession. Pursuant to his constitutional role as a national symbol, and in accordance with rulings by the Supreme Court of Japan, the emperor is personally immune from prosecution. By virtue of his position as the head of the Imperial House, the emperor is also recognized as the head of the Shinto religion, which holds him to be the direct descendant of the sun goddess Amaterasu. According to tradition, the office of emperor was created in the 7th century BC, but the first historically verifiable emperors appear around the 5th or 6th centuries AD.
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 1192, the emperors of Japan 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. 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 1868, 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 emperor has been relegated to an entirely ceremonial and representative role, without even nominal political powers. The emperor is the head of the Japanese honors system, conferring orders, decorations, medals, and awards in the name of the state and on behalf of its people in accordance with the advice of the Cabinet.
From 2001 to 2006, Japan discussed the possibility of changing the laws of succession to the Chrysanthemum Throne, which is currently limited to males in the male line of the Japanese imperial family.
As of December 2025, there are three people in the line of succession to the current emperor Naruhito: Crown Prince Akishino, Prince Hisahito, and Prince Hitachi. Prior to the birth of Prince Hisahito in 2006, the government of Japan considered changes to the Imperial Household Law to allow additional potential successors to the throne. Discussions to secure a stable imperial succession remain stalled.