Prince Naruhiko Higashikuni was a Japanese imperial prince, a career officer in the Imperial Japanese Army and the 30th Prime Minister of Japan from 17 August 1945 to 9 October 1945, a period of 54 days. He is the shortest-serving prime minister, resigning after eight weeks. An uncle-in-law of Emperor Hirohito twice over, Prince Higashikuni was the only member of the Japanese imperial family to head a cabinet and was the last general officer of the Imperial Japanese military to become Prime Minister. He was the founder of the Chiba Institute of Technology. He was one of the longest-lived members of any royal family.

The prime minister of Japan is the head of government and the highest political position of Japan. The prime minister chairs the Cabinet of Japan and has the ability to select and dismiss its ministers of state. The prime minister also serves as the commander-in-chief of the Japan Self Defence Forces and is a sitting member of either house of the National Diet. The current prime minister is Fumio Kishida of the Liberal Democratic Party, who assumed the office on 4 October 2021.