Incumbents
- Emperor: Akihito
- Prime Minister: Junichiro Koizumi (L–Kanagawa) until September 26, Shinzō Abe (L–Yamaguchi)
- Chief Cabinet Secretary: Shinzō Abe (L–Yamaguchi) until September 26, Yasuhisa Shiozaki (L–Ehime)
- Chief Justice of the Supreme Court: Akira Machida until October 15, Nirō Shimada from October 16
- President of the House of Representatives: Yōhei Kōno (L–Kanagawa)
- President of the House of Councillors: Chikage Ōgi (L–proportional)
- Diet sessions: 164th (regular, January 20 to June 18), 165th (extraordinary, September 26 to December 19)
Read more about this topic: 2006 In Japan