내각관방장관
Prime Minister Junichiro Koizumi appointed Hosoda to the Cabinet posts of Minister of State for Okinawa and Northern Territories Affairs, Minister of State for Science and Technology Policy, and Minister of State for IT Policy in 2002. Hosoda became Deputy Chief Cabinet Secretary in September 2003, and was promoted to Chief Cabinet Secretary and Minister of State for Gender Equality following Yasuo Fukuda's resignation in May 2004.