How did a right-wing populist party that began on YouTube win big in Japan’s recent election?

Sohei Kamiya, the leader of Japan's Sanseito party, speaks to the press after the upper house elections in Tokyo on July 20, 2025. (Manami Yamada/Reuters via CNN Newsource)

Its leader is a former supermarket manager who created his political party on YouTube in the depths of the coronavirus pandemic and campaigned on the Trumpian message “Japanese First.”

Now Japan’s burgeoning right-wing populist party Sanseito has emerged an unlikely winner in parliamentary elections this weekend.

Inspired by other populist right-wing groups that have sprung up in recent years, Sanseito bagged 14 seats in Japan’s upper house, according to public broadcaster NHK – a dramatic increase from the single seat it had occupied previously.

That might not sound like a lot in the 248-seat chamber, but it shows the party’s message is resonating with parts of the Japanese public.

The surprise success piles pressure on Prime Minister Shigeru Ishiba and his ruling Liberal Democratic Party, which after Sunday’s elections has now lost its majority in both the lower and upper houses.

Ishiba is facing calls to resign, which he has so far resisted.

Formed online

Sanseito’s rise is particularly notable given its unusual origins. Party leader Sohei Kamiya founded the group in 2020 by “gathering people on the Internet,” then gradually began winning seats in local assemblies, he said in a speech earlier this month. As of Monday, its YouTube channel has more than 460,000 subscribers.

It gained traction during the Covid pandemic, during which it spread conspiracy theories about vaccinations and a cabal of global elites, Reuters reported.

But in the run-up to the upper house elections, it became better known for its “Japanese First” campaign – which focused on complaints of overtourism and the influx of foreign residents.

It’s been an increasingly sensitive issue. The world’s fourth-largest economy has traditionally been strict on immigration, but in recent years worked hard to attract more international tourists and foreign workers to counter a rapidly aging population and plunging birth rates.

And it’s worked.

Japan’s population of foreign residents has jumped from 2.23 million to 3.77 million over the past decade, though that still only accounts for 3% of the total population of more than 120 million people.

Tourist numbers also keep breaking new records. But that’s caused problems in towns overwhelmed with visitors, some of whom behave badly, and depleting resources like the country’s famous hot spring waters.

Now, some believe there are too many foreigners in Japan – to the point the government recently formed a new task force to address the issue.

Sanseito tapped into these frustrations on its “Japanese First” platform, along with other complaints about stagnant wages, high inflation and costs of living.

“Right now, Japanese people’s lives are getting harder and harder,” said Kamiya – a former supermarket manager and English teacher – in his speech in July. He cited a lack of economic growth and widening wealth gap.

“More and more foreigners are coming (to Japan),” he warned. He added that he didn’t mind tourists, but claimed that relying on cheap foreign labor would harm Japanese wages, and that foreign workers who can’t find a good job would increase crime.

The party supports caps on the number of foreign residents in each town or city, more restrictions on immigration and benefits available to foreigners, and making it harder to naturalize as citizens.

Sanseito is also pushing for stronger security measures and anti-espionage laws, greater tax cuts, renewable energy, and a health system that leans away from vaccines.

It has urged greater defense capabilities, warning that Japan is “surrounded” by nuclear-armed countries and thus needs a “deterrent force” while pursuing long-term denuclearization.

MAGA comparisons

Kamiya also drew comparisons to other right-wing outfits like Donald Trump’s MAGA movement in the United States and the AfD (Alternative for Germany) party and Reform UK.

“Sanseito has become the talk of the town, and particularly here in America, because of the whole populist and anti-foreign sentiment,” said Joshua Walker, head of the US-based non-profit Japan Society, according to Reuters.

“It’s more of a weakness of the LDP and Ishiba than anything else,” he added.

Many have criticized Sanseito’s platform as xenophobic and discriminatory. Ahead of the election, he tried to tone down some of the party’s more controversial ideas and to attract more female voters, according to Reuters.

But he took a triumphant tone after the election results, Reuters reported. “The public came to understand that the media was wrong and Sanseito was right,” Kamiya said.

What’s next for Ishiba?

The results have left Ishiba’s coalition on extremely shaky ground.

He’d already lost control of the more powerful lower house in October, with the LDP losing its majority for the first time in 15 years – a stinging rebuke from Japanese voters to the longtime ruling party.

In a news conference on Monday, Ishiba called the upper house results a harsh judgment on the LDP and apologized to his party. He said the party would continue to rule with its coalition partner and work with other parties to cooperate on key issues.

Earlier on Sunday after polls closed, Ishiba had told NHK he intended to stay on as prime minister and party leader, citing the tariff talks with the US.

Japan is among a number of countries that will face a 25% tariff from August 1 onward under Trump’s newest measures – unless they’re able to strike a deal. At the news conference Monday, Ishiba said he wanted to speak with Trump as soon as possible to find a solution.

CNN’s Yumi Asada contributed reporting.

Written by Jessie Yeung, CNN