"Kimigayo" (君が代^?) is the national anthem of post-1868 Japan. It is also one of the world's shortest national anthems in current use, with a length of 11 measures and 32 characters. Its lyrics are based on a Waka poem written in the Heian period (794-1185), sung to a melody written in the imperial period (1868–1945). The current melody was chosen in 1880, replacing an unpopular melody composed eleven years earlier. While the title Kimigayo is usually translated as His Majesty's Reign, no official translation of the title nor lyrics has ever been established by law.

Prior to 1945, "Kimigayo" was the official national anthem of the Japanese Empire. When the Empire of Japan (imperial period) fell and its successor state, the State of Japan (democratic period) replaced it in 1945, the polity therefore changed from absolutism to democracy. However, just as Emperor Hirohito was not dethroned, so too was "Kimigayo" retained as the de facto national anthem, becoming legally recognized as such in 1999 with the passage of Act on National Flag and Anthem.