Shinjirō Koizumi | |
|---|---|
小泉 進次郎 | |
.jpg) Official portrait, 2025 | |
| Minister of Defense | |
| Assumed office 21 October 2025 | |
| Prime Minister | Sanae Takaichi |
| Preceded by | Gen Nakatani |
| Minister of Agriculture, Forestry and Fisheries | |
| In office 21 May 2025 – 21 October 2025 | |
| Prime Minister | Shigeru Ishiba |
| Preceded by | Taku Etō |
| Succeeded by | Norikazu Suzuki |
| Minister of the Environment | |
| In office 11 September 2019 – 4 October 2021 | |
| Prime Minister | Shinzō Abe Yoshihide Suga |
| Preceded by | Yoshiaki Harada |
| Succeeded by | Tsuyoshi Yamaguchi |
| |
| Assumed office 31 August 2009 | |
| Preceded by | Junichiro Koizumi |
| Personal details | |
| Born | (1981-04-14)14 April 1981 (age 44) Yokosuka, Kanagawa, Japan |
| Party | Liberal Democratic |
| Spouse | |
| Children | 2 |
| Parent(s) | Junichiro Koizumi (father) Kayoko Miyamoto (mother) |
| Relatives | Koizumi family |
| Education | Kanto Gakuin University (BEc) Columbia University (MA) |
Shinjirō Koizumi (Japanese:小泉 進次郎,Hepburn:Koizumi Shinjirō; born 14 April 1981) is a Japanese politician serving as theMinister of Defense since October 2025. He previously served as theMinister of the Environment from September 2019 to October 2021 andMinister of Agriculture, Forestry and Fisheries from May to October 2025. He has also served as aMember of the House of Representatives for theLiberal Democratic Party, representingKanagawa since2009. He is the second son of formerPrime MinisterJunichiro Koizumi and the younger brother of actorKotaro Koizumi.
After graduating from university, Koizumi worked as a researcher at theWashington-based think tankCenter for Strategic and International Studies, and became active politically as Young Leader of thePacific Forum CSIS. He also spent time working as a political secretary for his father in the final years of his second term as prime minister. In the2009 election, he was elected to the House of Representatives for the seat his father had occupied for more than 35 years.
After the election of theAbe Government in2012, Koizumi was appointed as a Vice-Minister for Reconstruction, focusing on the northeastern region of Japan that was devastated by theMarch 2011 tsunami and subsequentnuclear disaster. He publicly opposed his father's calls for Japan to abandon nuclear energy immediately. In 2019, Prime MinisterShinzo Abe appointed Koizumi to theCabinet asMinister of the Environment, a role he retained whenYoshihide Suga succeeded Abe as prime minister in September 2020. Koizumi endorsedTaro Kono in the2021 LDP leadership election, which resulted inFumio Kishida becoming prime minister. He subsequently left the cabinet and returned tobackbench politics. Koizumi ran as a candidate in the September2024 Liberal Democratic Party presidential election to succeed Kishida and was the third most voted in the country, losing the first round toSanae Takaichi andShigeru Ishiba, with the latter leading the final runoff. The LDP would lose its majority in the 2024 general election, after which Koizumi resigned as head of the party's Election Strategy committee. After working at the LDP's political reform headquarters, Koizumi was madeMinister of Agriculture by Ishiba in May 2025. Following Ishiba's announcement of his resignation, Koizumi again ran as a candidate in the October2025 Liberal Democratic Party presidential election, this time losing to Takaichi in the runoff. Takaichi subsequently appointed Koizumi asMinister of Defense.
Koizumi is a fourth-generation politician of theKoizumi family. His father,Junichiro Koizumi, was thePrime Minister of Japan from 2001 to 2006. His grandfather,Jun'ya Koizumi, was director general of theJapan Defense Agency (nowMinister of Defense) and a member of theHouse of Representatives representing Kanagawa's 2nd District, a seat that Junichiro also held. His great-grandfather,Matajirō Koizumi, wasMinister of Communications, mayor ofYokosuka and a member of theHouse of Peers.[1]
Koizumi's parents divorced when he was a toddler. His father gained full custody of him and his elder brother Kōtarō. They were raised by one of Junichiro's sisters, Michiko. At that time joint custody was not permitted in Japan. After the divorce, Shinjirō was estranged from his mother, Kayoko, and did not meet her or his younger brother Yoshinaga again until he reached adulthood.[2] Yoshinaga had not yet been born when their parents divorced, and was kept under the sole custody of Kayoko throughout his entire childhood.[3]
Koizumi was born and raised in Yokosuka, his father's home district. When he was a student in junior high and senior high schools, he was engrossed in playingsports, especiallybaseball.[4] He attendedKanto Gakuin University in Yokohama, receiving aBachelor of Economics degree in 2004. He received his master's degree in political science fromColumbia University.[5][6] He spent one year as a part-time research fellow at theCenter for Strategic and International Studies and as Young Leader of thePacific Forum CSIS before returning to Japan in 2007.[7]
Following his father's announced retirement in 2008, he was elected to his father's former seat representing theKanagawa 11th district in theAugust 2009 general election, in which many other LDP seats were lost to theDemocratic Party of Japan. He faced criticism for being a hereditary politician. He campaigned in a rented Toyota Prius with a volunteer staff.[8]
Koizumi became head of the LDP's young legislators caucus in October 2011, a post previously held by Prime MinistersTakeshita,Uno,Kaifu,Abe andAsō. In February 2012, he started a project called "Team 11," which sent members of the division to areas of theTōhoku region affected by the2011 Tōhoku earthquake and tsunami on the 11th of each month to talk to locals and report back on the state of the reconstruction efforts. The group had 82 members, all under the age of 45, as of March 2013. Some observers compared the group to the powerful "Machimura faction" led byNobutaka Machimura in terms of its political weight.[9]
He was critical of the LDP under party presidentSadakazu Tanigaki. In his first meeting as a party officer, he stated that "the image of the party is that it doesn't listen to the opinions of young people, has old thoughts and a hard head. That is why trust will not be restored."[10] He argued in a November 2011 speech that the party's stance on the controversialTrans-Pacific Partnership trade agreement needed to be clarified.[11] He later advocated breaking up the LDP's agreement with theDemocratic Party of Japan andKomeito to pass an overhaul of the social security and tax system, directly arguing to Tanigaki that the party's mission should be to take down the DPJ government and to restore LDP control, and drawing comparisons to his father's maverick reputation.[12]
Koizumi broke ranks with the LDP in August 2012 as one of seven LDP legislators who refused to walk out of the no-confidence vote instigated byIchiro Ozawa against Prime MinisterYoshihiko Noda, in which the LDP and NK had agreed to throw out their votes. Although Koizumi voted for the no-confidence resolution, it was ultimately voted down 246–86.[13] He voted forShigeru Ishiba againstShinzō Abe in the LDP leadership election of September 2012, but did not make his vote public until after the election in order to avoid influencing others' votes.[14]
Koizumi was re-elected in theDecember 2012 general election, which restored LDP control of the government under Abe. In the subsequentHouse of Councillors election in July 2013, he focused his campaigning efforts on disaster zones, outlying islands and areas in rapid population decline, giving speeches in support of their local LDP candidates. Kenichi Tokoi, a nonfiction author who wrote a book about Koizumi, said that his goal was to shake as many individual hands as possible and to leave the impression that he was kind enough to visit them, something which he could not achieve by campaigning in big cities.[15]
In October 2013, he was appointed Parliamentary Secretary in charge of Tohoku Recovery, in which capacity he would oversee post-disaster reconstruction efforts inIwate Prefecture andMiyagi Prefecture. Ishiba, then secretary general of the LDP, stated that Koizumi "made a very strong case" with local disaster victims "about what he wanted to do and why."[16] Tokoi characterized this posting as a test of Koizumi's administrative ability.[15]
Koizumi was reportedly considered for a formal cabinet post under the Abe government in the reshuffles of October 2015 and July 2017.[17][18] On 11 September 2019, Abe appointed Koizumi asMinister of the Environment.[19][20] He advocated for environmentalist policies, including ending Japan's use of nuclear and coal power, despite serving in a government considered skeptical of such policies.[21][22][23][24]
However, he supports the construction of newcoal-fired power stations in Japan, despite theirparticulate andgreenhouse gas emissions. His support for the construction of two coal-fired power stations inYokosuka has led him to be a "a target of activists' wrath".[25]
In late August 2020, after the resignation ofShinzo Abe, Koizumi was named as a possible successor.[26] AKyodo News survey showed that almost 9% of those surveyed preferred him for prime minister,[26] though some inside the party consider him too young to be in charge of the country.[27] Koizumi declined to run and endorsed Minister of DefenseTarō Kōno for the position.[28] After Kōno also declined to run Koizumi and Kono both endorsedChief Cabinet SecretaryYoshihide Suga, a fellow Kanagawa politician.[29] Suga ultimately won the LDP presidential election and became prime minister.[30] Suga decided to retain Koizumi in his role.[31] Poor approval ratings and criticism of the government's handling of theCOVID-19 pandemic led to Suga announcing his resignation in September 2021.[32] In the party's leadership election of 2021 (which ended withFumio Kishida being elected as leader and later prime minister), Koizumi again endorsed Kōno for the position.[33][34] When Kishida formedhis first cabinet in October, Koizumi was replaced byTsuyoshi Yamaguchi as Environment Minister.[35]
From 2021 to 2024, Koizumi remained abackbencher in the Diet. He was chosen to chair the standing committee on national security of the House of Representatives in January 2024 after the previous chairman resigned in connection to the2023–2024 Japanese slush fund scandal.[36]
On 14 August 2024, Prime Minister Fumio Kishida announced he would not seek a second term as LDP President, making the race an open field.[37][38] By late August, both Kono and Ishiba had already declared their respective candidacies.[39][40]
On 6 September, Koizumi officially announced his candidacy for the LDP presidency.[41][42][43] In a press conference he pledged to introduce legislation that would legalize separate surnames for married couples and proposed holding a national referendum to determine whether or notArticle 9 of theConstitution should be amended.[44][45] Koizumi promised to dissolve thelower of house and call a general election “as soon as possible” if elected President and later Prime Minister.[46][47] His candidacy was endorsed by former prime ministerYoshihide Suga.[48] Koizumi gave his first street speech the following day in Tokyo'sGinza district.[49] Koizumi, along with fellow front-runnerShigeru Ishiba, has been described as one of the "centrists" of the election.[50][51][52]
Koizumi lost the election, placing third behindSanae Takaichi and Shigeru Ishiba. Ishiba defeated Takaichi in a runoff election, having received support from Koizumi's camp. As LDP president, Ishiba appointed Koizumi chairman of the Election Strategy Committee, a senior party office.[53] In theOctober 2024 election Koizumi traveled across the country to rally support for LDP candidates, but the results were unfavourable, with the ruling coalition losing its majority. Koizumi resigned as election strategy chairman to take responsibility.[54] He was replaced bySeiji Kihara as the party's election chief.[55] Koizumi was subsequently appointed as executive secretary to the LDP political reform headquarters.[56]
When asked in February 2025 about the possibility of running for party leadership again, Koizumi didn't rule it out, saying "I will do my best to become a politician that people want to support."[57] Later that month, Koizumi suggested that theKansai-based oppositionInnovation Party should join the LDP-Komeitocoalition, amidst budget negotiations that were taking place in the lower house.[58] He continued to advocate for this, stating “we should officially ask for a coalition” in March. Koizumi simultaneously criticized the possibility of agrand coalition with theConstitutional Democratic Party, the chief opposition party.[59]
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On 21 May 2025,Agriculture, Forestry and Fisheries MinisterTaku Etō submitted his resignation to Prime Minister Shigeru Ishiba, after stating on 18 May that he had never bought rice, and was instead provided with a free supply of it from his local constituents; the comments were considered to be inconsiderate amidst a nationwide riceshortage, and reportedly upset Ishiba.[60][61] Koizumi, having chaired the LDP's Agriculture & Forestry Division and its Comprehensive Fisheries Policy Research Council, was immediately seen as the most likely successor to the disgraced Etō, who had been sacked by Ishiba.[62][63] Koizumi was appointed Agriculture Minister by Ishiba on the same day.[64][65] He stated that Koizumi's main objective in the new role would be to stabilize rice prices.[66] Etō and Koizumi had a testy relationship dating back 10 years when the former reportedly told Koizumi, who is 20 years his junior, "I hate you". However the two reportedly became friends after Koizumi invited Etō to dinner at some point afterwards.[67]
I thought that Mr. Koizumi has experience, insight, and passion for reform in both agriculture and the fisheries industry.
Koizumi's first official act as Agriculture Minister was to temporarily suspend bidding for stockpiled rice.[69] He also confirmed to reporters that he himself had purchased rice for his family.[70] Upon taking up the new role, Koizumi styled himself as the “Minister in Charge of Rice.”[71] At a speech given at theMinistry of Agriculture, Forestry and Fisheries the day following his appointment, Koizumi emphasized the importance of reducing rice prices, saying he felt "a sense of crisis" and would seek to restore public trust in the ministry.[72] Koizumi sought to enact swift reforms at the ministry upon his appointment. At his inaugural press conference the previous day, he told reporters that the government would temporarily cancel the fourth bidding process for stockpiled rice that was originally scheduled for later in May, and said he was considering cancelling competitive bidding for the rice in favor of selling it directly to supermarkets and the food service industry through discretionary contracts.[73][74] Koizumi stated that the goal of the ministry would be to lower rice prices to ¥2,000 per 5 kilograms by June.[75][76]
After Prime Minister Ishiba resigned, Koizumi announced his second leadership candidacy in September 2025 for the2025 leadership election.[77] In opinion polls throughout the election, Koizumi and former Economic Security MinisterSanae Takaichi were seen as the frontrunners as they both polled in first place various times.[78][79]
On September 24,Bunshun Online reported possiblestealth marketing by Koizumi's campaign, citing an e-mail by his public relations chiefKaren Makishima giving associates examples of comments to make online to promote Koizumi.[80][81][82] Koizumi acknowledged the facts and apologised on 26 September, but denied having been aware of it. Makishima resigned from the campaign.[83] This led to his campaign receiving several death threats and bomb threats, however Koizumi stated his intent to keep running in the election.[84]
On 4 October, Takaichi came in first place during the first round of voting with 183 (31.07%) of the vote.[85] Koizumi came in second with 164 (27.84%) of the vote, meaning that both Koizumi and Takaichi advanced to the run-off to elect the party leader.[86] Takaichi would go on to defeat Koizumi in the run-off by a 54% to 46% margin.[87]
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On 21 October 2025, Koizumi was appointed asMinister of Defense byPrime MinisterSanae Takaichi.[88][89]
At his inaugural press conference the following day, he told reporters that he wants to ease the country's rules on defense equipment exports, and move up the revision of the government's three key defense and security policy documents.[90]
On 29 October 2025, one week after becoming Defense Minister, Koizumi held talks withUnited States Secretary of DefensePete Hegseth inTokyo.[91]
Like his father, Koizumi visitsYasukuni Shrine on 15 August, the anniversary of Japan's surrender in World War II. He visited in 2012, 2013, and again in 2022.[92][93][94] He visited in 2024 in preparation for his run in the2024 LDP leadership election.[95] Koizumi visited the shrine again in 2025, on the 80th anniversary of the end of World War II.[96]
In a May 2013 interview with theSankei Shimbun, he refused to comment on Osaka mayorToru Hashimoto's controversial remarks oncomfort women, characterizing the issue as one that should be discussed among experts and historians rather than politicians. He described the perceived nationalist shift in Japanese politics as "Chinese propaganda" and stated that the government needed to wage a better public relations campaign against it while focusing on the successful implementation ofAbenomics. He also commented on theJapanese Constitution, stating that amendments were necessary but that there were more immediate problems to be solved: "I go to the disaster zones in Tohoku every month, and the constitution has not come up even once as an issue when I walk down the street there."[97]
Koizumi was critical of the Abe government's decision to terminate a corporate tax surcharge intended to fund the Tohoku recovery, and viewsnuclear power as unsustainable in the long term, mirroring views that his father expressed in 2013.[16]
In 2017, when asked on his position onsame-sex marriage in a survey conducted byThe Asahi Shimbun, Koizumi did not give a response.[98] In a 2021 survey conducted byNHK, he said he was in favor of its legalization.[99] When asked again in August 2024, Koizumi did not respond.[100] In a 2024 survey conducted by NHK for thegeneral election held in October of that year, Koizumi affirmed his support for legalization.[101] When asked again by NHK ahead of the2026 general election, Koizumi stated his opposition to legalization of same-sex marriage for the first time.[102]
Koizumi opposes a ban on corporate donations to political campaigns and parties, arguing that politics shouldn't be "funded entirely by tax money."[103]
He is in favor of allowing selective surnames for married couples. During the2024 LDP leadership election, Koizumi claimed he would submit a bill into the Diet that would legalize such a system. He later stated that LDP members of the Diet should be free to vote on any legislation related to the matter based on their own views, rather than be restricted to a party consensus.[104]
Speaking on the LDP’s culture in March 2025, Koizumi stated that "the one thing that needs to change in the culture of the LDP is that as soon as approval ratings drop, we immediately try to drag the leader down". The comments came while some within the party had been calling for Prime Minister Ishiba to resign following news of a scandal.[105]
Koizumi had a 75.6% approval rating at the start of his stint as parliamentary secretary for Tohoku recovery.[106] In a December 2013JNN poll, he ranked second after Shinzo Abe as the most favoured candidate for prime minister, although 57% responded that they had no particular favoured candidate.[107] In April 2017, in the aftermath of theMoritomo Gakuen scandal surrounding Prime Minister Abe, polls by Yomiuri[108] and NTV[109] showed Koizumi as the most favoured LDP leader (and presumptive prime minister), surpassing both Abe and challengerShigeru Ishiba.[110]
Following the December 2012 election, theNational Diet Building gift shop began selling "Shinji-Rolls"(進次ろうる), souvenir green tea-flavoured roll cakes branded with Koizumi's likeness. Shinji-Rolls became the gift shop's second most popular item in 2013, outselling souvenirs branded with the likenesses of LDP leaders Shigeru Ishiba and Taro Aso, and outsold only bymanju bearing the likeness of Shinzo Abe.[111]
The Nikkei stated in 2025 that Koizumi possessed some of the 'best communication skills' in Japanese politics.[112]
On 7 August 2019, television announcer and news presenterChristel Takigawa announced that she married Shinjiro Koizumi. She gave birth to a son on 17 January 2020.[113] She gave birth to a daughter on 20 November 2023.[114] In January 2020, Koizumi received international news attention when he announced his plans to take two weeks of paternity leave when his first child was born.[115][116]
Along withJapanese, Koizumi can speakEnglish.[117][118]
He is the secretary-general of the Surfing Diet League of the LDP.[119] In September 2023, he surfed on the coasts ofFukushima to dispel concerns regarding the discharge of waste from thedecommissioned Fukushima nuclear plant.[120] He returned to Fukushima Prefecture in July 2024 to surf withU.S. Ambassador to JapanRahm Emmanuel while having summer vacation.[121]
Koizumi is also known for visiting "cat cafes" and posting photos to social media about his interactions with cats, with whom he said to be "very popular".
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若者の意見を聞かない、考えは古い、頭は固いというのが党のイメージだ。だから信頼が回復しない。
The name of Shinjiro Koizumi, 39, now environment minister and the son of charismatic former Prime Minister Junichiro Koizumi, is often floated as a future prime minister, but many consider him too young.
resultsJT was invoked but never defined (see thehelp page).{{cite web}}:line feed character in|title= at position 50 (help)
| House of Representatives (Japan) | ||
|---|---|---|
| Preceded by | Representative forKanagawa 11th District 2009–present | Incumbent |
| Preceded by | Chairman of the Committee on National Security 2024 | Succeeded by |
| Political offices | ||
| Preceded by | Minister of the Environment 2019–2021 | Succeeded by |
| Preceded by | Minister of Agriculture, Forestry and Fisheries 2025 | Succeeded by |
| Preceded by | Minister of Defense 2025–present | Incumbent |
| Party political offices | ||
| Preceded by | Director of the Youth Division, Liberal Democratic Party 2011–2013 | Succeeded by |
| Preceded by | Chairman of the Election Strategy Committee, Liberal Democratic Party 2024 | Succeeded by |
| Environment Agency Director General | |
|---|---|
| Environment Agency Director General Director in Charge of Global Environmental Problems | |
| Minister of the Environment Minister in Charge of Global Environmental Problems | |
| Minister of the Environment | |
| Defense Agency Director General |
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|---|---|
| Minister of Defense |
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Defence ministers of theG20 | |
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| International | |
|---|---|
| National | |
