The success of the Sanseito party could reshape Japan’s domestic and foreign policy. It also aligns Japan with political trends in many other parts of the world.

A fringe far-right populist party Sanseito was one of the biggest winners in the weekend's upper house election, attracting many voters with “Japanese First" platform that included calling for tougher restrictions on foreigners and the curtailment of gender equality and diversity policies.

Anti-establishment parties focused on wages, immigration and an unresponsive political elite struck a chord with working-age people in Japan.

The ruling LDP and its junior partner Komeito both suffered significant losses amid widespread concerns over the rising cost of living and hostility to the political establishment as a whole.

The fringe far-right Sanseito party emerged as one of the biggest winners in Japan's upper house election, gaining support with warnings of a "silent invasion" of immigrants.

Japan’s voters dealt Prime Minister Ishiba Shigeru of the Liberal Democratic Party (LDP) with yet another devastating blow on Sunday, the second electoral loss since coming into office last fall.

Sanseito, a Japanese populist party that draws inspiration from Donald Trump's politics, is gaining support ahead of Sunday's upper house elections, suggesting a notable shift in the country's traditionally centrist landscape.

The era of predictable elections is over, though Prime Minister Ishiba vows to remain in office. Mr. Kirk, based in Seoul and Washington, has been covering Asia for decades for newspapers and magazines and is the author of books on Korea, the Vietnam War and the Philippines.