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.
Since the democratic period began, there has been controversy over the performance of the anthem at public ceremonies. Along with the Hinomaru flag, "Kimigayo" has been claimed to be a symbol of Japanese nationalism, imperialism and militarism, with debate over whether "Kimigayo", as a remnant of Japan's imperial past, is compatible with Japanese democracy. Thus, essential points of controversies to the Hinomaru and "Kimigayo" are whether they express praise or condemnation to the Empire of Japan and whether the Empire of Japan (pre-1945) and the State of Japan (post-1945) are the same states or different states.