The Imperial Household Agency (IHA) is an agency of the government of Japan in charge of state matters concerning the Imperial Family, and the keeping of the Privy Seal and State Seal of Japan. From around the 8th century AD until the Second World War, it was known as the Imperial Household Ministry .

The Imperial House , also referred to as the Imperial Family and the House of Yamato, is the imperial family of Japan, consisting of those members of the extended family of the reigning Emperor of Japan who undertake official and public duties. Under the present Constitution of Japan, the emperor is "the symbol of the State and of the unity of the people". Other members of the Imperial Family perform ceremonial and social duties, but have no role in the affairs of government. The duties as an emperor are passed down the line to their male children. This Japanese monarchy is the oldest continuous hereditary monarchy in the world.