Conservative Sanae Takaichi was elected Japan's first female prime minister after a vote in a lower house of parliament on Tuesday.

She immediately set about naming the cabinet that she hopes will bring about the social, economic and national security changes that she will need if her administration is to avoid the short lifespan of many recent Liberal Democratic Party (LDP) governments.

Takaichi won 237 of the 465 votes cast in Japan's lower house of Parliament for the post of prime minister, her conservative LDP supported by its new coalition partner, the right-leaning Japan Innovation Party (JIP).

Based in Osaka and presently very much a minority regional party, the JIP has ambitions to broaden its electoral appeal across Japan.

Despite some sharp political differences with the LDP, the JIP's leadership anticipates that a stint in the ruling coalition will confer political legitimacy and help extend its electoral reach.

Given the scale of the challenges that the new government is facing, however, it is equally possible that a disappointed electorate will turn on both the LDP and the JIP at the next election.

And that means Takaichi has no time to lose if she wants to last longer than her immediate predecessor, Shigeru Ishiba, who formally stepped down on Tuesday morning after 386 days in office.

First priority: Heal the LDP rift

"The first priority for the new prime minister will be to heal the deep rift within the party and to rebuild public trust in the LDP," said Jeff Kingston, director of Asian Studies at Temple University Japan (TUJ).

"At the same time, she has to figure out how to make this strange coalition work," he told DW. "At the moment, the alliance appears to be based on vague promises and an agenda with no timeline."

The priority for the vast majority of ordinary Japanese will be policies that at least reduce the "economic pain" that they are feeling, Kingston said.

"There is a sense of economic malaise and the new government must find ways to address high prices for household necessities as most just feel they are underwater at the moment."

An avowed disciple of the late former Japanese Prime Minister Shinzo Abe, Takaichi is expected to revive many of his policies, said Naomi Fink, chief global strategist for Amova Asset Management in Tokyo.

The Tokyo Stock Exchange reacted positively to the appointment of Takaichi, a known supporter of expansive fiscal policy and monetary easing measures. The Nikkei stock index ended Tuesday at an all-time high above 49,000 points on anticipation of greater stability in Japan's domestic political situation.

High costs, stagnant wages

Yet concerns remain over stagnant wage growth and an increasing percentage of Japan's working population in non-permanent positions, another issue that Takaichi will need to address swiftly.

Tadashi Anno, a professor of politics at Tokyo's Sophia University, points out that the electorate demonstrated its dissatisfaction with the LDP in July's election for the upper house of parliament — a disastrous showing for the party, which was already in a minority government and a result that ultimately ended Ishiba's term in office.

"People expressed their feelings over the state of the economy, the weak yen and rising prices," he said, adding that while the LDP and JIP have discussed a plan to reduce prices of daily necessities, it remains unclear how quickly legislation can be passed and helps people make ends meet.

Another challenge looming on the immediate horizon is the three-day official visit of US President Donald Trump, who is due to arrive in Tokyo on Monday before going on to South Korea.

While Japan appears to have sated the president with a $550 billion (€473 billion) investment package, Tokyo is still concerned that he may arrive with additional demands.

"Trump is very unpredictable," Anno said. "On the security front, Japan made a major policy change in 2022 by committing to spending 2% of GDP on defense. But there is the sense that the US believes Japan needs to be doing more and I think it is likely that the US will put new pressure on Japan on that front."

The government's financial situation might make that difficult, he said, but Tokyo will be acutely aware that Trump has in the past threatened to withdraw US forces from allied nations, notably Japan and South Korea, should they not accede to his demands. Takaichi will be doing her very best to avoid being given an ultimatum on that issue.

By law, Takaichi does not have to call another general election until the autumn of 2028 and she will hope to muddle through in her alliance with the JIP on key issues, most notably the budget that needs to be approved by the end of February.

But given that she heads a government without a majority, a united opposition can make political life very difficult for her.

Coalition ally seeks flexibility

"The JIP does not have any cabinet members so it is clear they are seeking flexibility in their alliance with the LDP," said Anno.

"That makes the future of the coalition shaky. If the JIP wants to realize some of its policies then it will stick with the LDP, but I do not see this lasting for the long term."

Kingston concurs.

"The JIP is not going to be able to help the LDP electorally, like its previous coalition partner Komeito did, and I estimate that will cost the LDP 20% of its seats at the next election," he said.

"I estimate this government will last around a year and that Japanese politics is going back into cycles of prime ministers serving one year before being forced to step down," he said.

The only certainty going forward, he said, is instability.

Edited by: Keith Walker