"Kimigayo" (君が代) is the national anthem of Japan. The lyrics are from a waka poem written by an unnamed author in the Heian period (794–1185), and the current melody was chosen in 1880,replacing an unpopular melody composed by John William Fenton in 1869. While the title "Kimigayo" is usually translated as "His Imperial Majesty's Reign,” no official translation of the title or lyrics have been established in law.
In the Kamakura period, "Kimigayo" was used as a festive song among samurai, and then became popular among the people in the Edo period. In the later part of the Edo period, "Kimigayo" was used in the Ōoku (harem of Edo Castle, current Tokyo Imperial Palace) and Satsuma-han (current Kagoshima Prefecture) as a common festive new year song. In those contexts, "kimi" never meant the emperor, but only the Tokugawa shōgun, the Shimazu clan as rulers of the Satsuma-han, guests of honour, or all members of a festive drinking party. After the Meiji Restoration, samurai from Satsuma-han controlled the Imperial Japanese government, and they adopted "Kimigayo" as the national anthem of Japan. From this time until the Japanese defeat at the end of World War II, "Kimigayo" was understood to mean the long reign of the Emperor. With the adoption of the Constitution of Japan in 1947, the Emperor became no longer a sovereign who ruled by divine right, but a human who is a symbol of the state and of the unity of the people as a constitutional monarch.[6] The Ministry of Education did not give any new meanings for "Kimigayo" after the war; this allowed the song to mean the Japanese people. The Ministry also did not formally renounce the pre-war meaning of "Kimigayo".
From 1888 to 1945, Kimigayo served as the national anthem of the Empire of Japan. When the Empire accepted the Potsdam Declaration and came under Allied occupation, Emperor Shōwa retained the throne, and Kimigayo remained the de facto national anthem to preserve the Japanese monarchy. The passage of the Act on the National Flag and Anthem in 1999 officially recognized it as both the national and imperial anthem.
In 1999, during the deliberations of the Act on National Flag and Anthem, the official definition of Kimi or Kimi-ga-yo was questioned repeatedly. The first suggestion, which was given by Chief Cabinet Secretary Hiromu Nonaka, stated that kimi meant the "Emperor as the symbol of Japan", and that the entire lyrics wish for the peace and prosperity of Japan. He referred to the new status of emperor as established in Article 1 of the Constitution of Japan as the main reason for these suggestions.
The lyrics and musical notation of the anthem are given in the second appendix of the Act on National Flag and Anthem. As for the sheet music itself, it displays a vocal arrangement with no mention of tempo and all of the lyrics in hiragana. The anthem is composed in 4/4 (common time) in the Dorian mode.