Ishiba, Koizumi, Kamiya: What Japan’s election upset means for its leaders and future

Japan's Prime Minister Shigeru Ishiba - File Photo

Japan’s long-dominant Liberal Democratic Party (LDP) has suffered a major political setback, losing its grip on the Upper House of Parliament in an election that delivered a sharp rebuke from young and middle-aged voters. Prime Minister Shigeru Ishiba’s coalition lost 19 of its 66 seats up for re-election, pushing the LDP into minority status in both houses of Parliament and triggering calls for his resignation, the New York Times reported.

While the LDP has weathered political storms before, this election marked a dramatic shift. The biggest winners were two relatively new right-wing nationalist parties: the Democratic Party for the People, led by Yuichiro Tamaki, and Sanseito, headed by Sohei Kamiya. Both groups capitalized on growing public frustration with inflation, immigration, and political stagnation—issues that the LDP, many voters feel, has failed to adequately address.

A new generation turns right

The Democratic Party for the People gained 13 seats in the Upper House, more than doubling its total to 22. Sanseito also made impressive gains, securing 13 seats and increasing its tally to 15. Voters under the age of 50 helped fuel this surge, drawn by populist rhetoric that promised wage hikes, lower foreign worker numbers, and policies that would benefit younger generations.

While the LDP continues to hold sway with voters over 65, who make up nearly 30 percent of the electorate, younger voters showed a clear appetite for political alternatives. “It wasn’t about agreeing with everything,” one voter in Tokyo said. “It was about sending a message to the people in power that we’ve had enough.”

A rising challenger in Koizumi

One figure drawing significant attention within the LDP is Shinjiro Koizumi, the 44-year-old son of a popular former prime minister and a current cabinet minister. Known as a reform-minded “rice minister,” Koizumi has cultivated a public image of youthful energy and nationalist pride. Many within the party see him as a potential successor to Ishiba—especially after the current prime minister’s lacklustre performance in this campaign.

Inflation and rice at the ballot box

The cost of living, especially soaring grocery prices, dominated campaign narratives. With inflation running above 3%—a rate not seen in decades—many voters cited the price of rice as their top concern. A poor harvest combined with government policy has caused the cost of Japan’s most essential staple to double in recent months. A national survey found 28 percent of voters prioritized food prices over even major issues like immigration and national security.

Trade friction with the US

A looming trade crisis with the United States also shaped voter sentiment. The Trump administration has threatened to impose a 25 percent tariff on all Japanese exports unless Tokyo agrees to expand American access to Japan’s rice market and commit to buying more US-made cars. After seven rounds of unsuccessful trade talks, many Japanese voters feel caught between economic pressure from abroad and inaction at home.

Immigration divides the electorate

Immigration also loomed large, with Japan having accepted nearly one million foreign workers over the past three years to address a declining labour force. Foreigners now account for roughly 3 percent of the population. Sanseito in particular seized on nationalist sentiment, calling for tighter immigration controls under the slogan “Japanese First”—a nod to former U.S. President Donald Trump’s rhetoric.

What next for Ishiba—and for Japan?

At 68, Prime Minister Ishiba is facing mounting pressure to step down. His appeal to stand firm against foreign pressure and protect domestic farmers fell flat with many voters, especially in urban areas. Whether he will resign or attempt to regroup remains uncertain.

Meanwhile, the ascendance of Tamaki and Kamiya could reshape Japan’s political future. Tamaki’s more moderate Democratic Party may position itself as a coalition partner in the coming months, while Kamiya’s Sanseito rides a wave of right-wing populism.

The election has exposed a generational divide and laid bare the vulnerabilities of Japan’s aging political elite. Whether this represents a fleeting protest vote or a long-term realignment will depend on how these new parties perform—and whether Japan’s political old guard can adapt to the country’s rapidly changing landscape.