Hosoda left government service in 1986 to become a secretary to his father, Kichizo Hosoda (1912–2007), who was then a member of the House of Representatives. He was elected to the House of Representatives for the first time in the 1990 general election, representing the Shimane Prefecture at-large district, which had previously been his father's constituency.[2]
Koizumi government
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.[1]
Aso government
After Tarō Asō was elected to the LDP presidency and became Prime Minister, Hosoda was appointed Secretary-General of the LDP. He served in this post from September 2008 to September 2009,[3] when he resigned following the party's historic defeat in the 2009 general election.[4]
Abe government
Following Shinzo Abe's victory in the 2012 LDP presidential election, Abe appointed Hosoda to head the Seiwa Seisaku Kenkyukai (Seiwa-kai), the largest faction in the party, replacing Nobutaka Machimura.[5] The faction is now commonly known as the "Hosoda faction".[6]
Hosoda briefly served as Acting LDP Secretary-General following Sadakazu Tanigaki's hospitalization for a spinal cord injury in July 2016.[7] In August 2016, Hosoda was appointed Chairman of the LDP General Council.[8]
Hosoda chaired the LDP's 2018 task force on reforming the Constitution of Japan, drawing up a four-point revision proposal in March 2018 that included an amendment to Article 9 to make explicit reference to the Self-Defense Forces.[9][10] Abe named Hosoda as head of the LDP Headquarters for the Promotion of Revision of the Constitution in September 2019, replacing Hakubun Shimomura, who was viewed as more "dogmatic" than Hosoda and had antagonized opposition parties.[11][12]
Hosoda was a member of the LDP Parliamentary Group on the Promotion and Conservation of Japanese Sword and Ironwork Culture, which supported subsidies for Tatara steel.[13]
On 10 November 2023, Hosoda died of multiple organ failure at the hospital in Tokyo, at the age of 79, just one month after he resigned from the House of Representatives.[17] After stepping down as chairman, Hosoda was reportedly hospitalized and absent from plenary sessions, but says that his condition suddenly deteriorated the day before his death.
^"Kishida forms 2nd Cabinet on heels of election". Yomiuri Shimbun. 11 November 2021. Retrieved 13 November 2023. Prior to the Diet vote on the prime minister, former Chief Cabinet Secretary Hiroyuki Hosoda, 77, of the LDP was elected as lower house speaker, and former economy minister Banri Kaieda, 72, of the Constitutional Democratic Party of Japan was chosen as vice speaker during the afternoon plenary session.
^"細田博之前衆院議長が死去 官房長官や自民幹事長務める". The Nikkei (in Japanese). Nikkei Inc. 10 November 2023. Archived from the original on 10 November 2023. Retrieved 10 November 2023.