Kishida has offered an alternative to what he sees as ‘neoliberal’ policymaking, promising a more active government that intervenes in the market, providing financial assistance packages to the more needy in Japan and subsidies for daycare. He has also vowed to reform the LDP from within, limiting the terms of senior executives to three years, possibly a blow to faction heads.

Despite promises of an open LDP leadership election, vested factional interests were very much part of the politics of this campaign. Navigating factional interests may well be a key feature of Kishida’s time as prime minister.

During the campaign, both Kishida and the other front runner, the popular administrative reformer and minister responsible for Japan’s vaccine rollout, Taro Kono, vowed not to allow factional considerations to dominate their choices for cabinet. But Kishida has not stuck to this promise completely. Although Kishida has nominated younger lawmakers to cabinet posts, deals struck during the campaign may well affect his ability to fully control his agenda, and his longevity as prime minister may suffer because of factional manoeuvring.

Factions are endemic to Japanese politics. They had their heyday in the 1970s–80s when two massive factions led by Kakuei Tanaka and Takeo Fukuda competed for dominance within the party.

During these ‘Kaku-Fuku wars’, prime ministers were often short-term disposable functionaries, and real power resided in the testosterone and tobacco fuelled negotiations that took place behind closed doors. Nowadays, partly as the result of electoral system reform in the 1990s, factions are somewhat more benign and fractured.

In this campaign, factions weren’t supposed to matter. Six of the seven LDP faction heads — all but Kishida — declared publicly that they would not mandate loyalty among their supporters to any one candidate. In reality, there was considerable movement behind the scenes, particularly around two other candidates in the race.

Japan’s longest serving prime minister Shinzo Abe — not a faction head but influential within the largest faction of the party — threw his weight behind ideological bedfellow Sanae Takaichi. Meanwhile, there were reports that faction head and party Secretary General Toshihiro Nikai was quietly telling his supporters they could vote for Takaichi or Seiko Noda, the two candidates least likely to win. While Nikai’s intentions were unclear, increased support for the outside candidates would deprive the frontrunner of an absolute majority. According to party rules, such a situation triggers an immediate run off, where rank-and-file members do not vote, thus lending more power to faction heads who have greater control over Diet members.

Indeed, in the last few days of the campaign, when a run-off was inevitable, faction heads and ambitious politicians within the LDP abandoned all pretence of an open election. The night before the vote, staff from Takaichi’s and Kishida’s campaign stitched up a deal where they would support each other if one of them faced Kono in the second round of voting. It’s clear from election results that other faction heads sensed a run-off and pulled in behind Kishida as well.

As a politician, Kishida is somewhat predictable, and probably won’t move hard against the factions despite his promises to reform the LDP. Kono has conversely shown a proclivity to act without coordinating first with the party — a challenge to factional dominance — such as when he cancelled a major missile defence project as defence minister.

In choosing Kishida, the factions have taken a calculated risk. Kono would likely have secured the LDP a larger win in the general election that will now be held on 31 October. Kono even ranked higher as preferred prime minister than Constitutional Democratic Party (CDP) leader Yukio Edano among supporters of the CDP.

Still, Kono’s popularity is an external source of power that poses another challenge to the factions. Kishida’s performance in the election won’t necessarily be stunning, but all signs are that it will likely be better than expected under his predecessor, the unpopular Yoshihide Suga, who was prime minister for just one year. Indeed, under Kishida, the LDP may retain its outright majority in the lower house, particularly if voter turnout is depressed through a lack of interest. Even if it doesn’t retain its majority, the LDP will almost certainly still be able to rely on its coalition partner, Komeito, to retain power.

But the factions will likely demand posts either within the party, on committees or even in cabinet for their support. Takaichi has received a plum position as chairperson of the LDP Policy Research Council, through which Abe will continue to exert influence. Takaichi is a defence hawk with authoritarian tendencies. As internal affairs and communications minister she claimed she had the power to shut down media companies if they did not adequately and accurately report the government’s position.

Her priorities include revision of the constitution, and her preference for such reform is more comprehensive than the changes Kishida has endorsed. Her enthusiasm for revision will also likely be higher than that of Kishida, who will want to avoid fractious debates around the constitution such as those that rocked the nation when Abe pushed ‘reinterpretation’ in 2014–15.

It’s an open question as to whether Kishida has the skill to balance the competing interests within his party, as well as perhaps those of Komeito. As yet, there is nothing to suggest he has the mettle of former prime minister Junichiro Koizumi who managed to bring the factions to heel, or Abe, who managed to balance and control them. If the balancing game proves too much, we should not necessarily expect him to last much longer than Suga.

Bryce Wakefield is the national executive director of the Australian Institute of International Affairs (AIIA) and a visiting fellow at The Australian National University.