A political group pressing for restructuring Osaka into a metropolis like Tokyo to seek more efficient governance gained momentum Sunday in winning local elections to choose a new mayor and prefectural governor.

The group, Osaka Ishin no Kai, which has been struggling to rekindle the plan after it was rejected in a referendum in 2015, saw its head and former governor, Ichiro Matsui, elected as new mayor and its policy chief and former mayor, Hirofumi Yoshimura, elected as governor.

(Ichiro Matsui, left, and Hirofumi Yoshimura at a press conference after the elections.)

"We'll proceed with discussions carefully while listening to opponents and will eventually let residents make the decision," Matsui, 55, said at a joint press conference where Yoshimura, 43, said, "I want to give another try (to the reform plan)."

An exit poll by Kyodo News showed that 57.6 percent of residents in Osaka city endorsed the metropolis plan while 40.2 percent opposed it.

Calling another referendum would require approvals from both the prefectural and municipal assemblies, which also came up for election Sunday.

Osaka Ishin did not have a majority in the assemblies before the elections, asking cooperation from a local chapter of Komeito, the junior coalition partner of Prime Minister Shinzo Abe's Liberal Democratic Party.

"We take the will of the voters seriously," Shigeki Sato, a lower house member from Komeito who heads its Osaka chapter, told reporters after the elections.

Matsui and Yoshimura abruptly stepped down from their previous positions last month to switch their jobs in Sunday's elections, which came as part of local polls across Japan.

They beat candidates backed by the LDP and also supported by local chapters of major opposition parties.

The metropolis plan was originally drafted by former Osaka Gov. and Mayor Toru Hashimoto, who sought to reorganize the administration of the western Japan city into a government similar to Tokyo's in a bid to save hundreds of billions of yen in taxpayers' money by reducing functional overlaps between the prefectural and city governments.

But in the May 2015 referendum, voters dismissed the argument, with both ruling and opposition parties insisting that many costs could be cut without the reform.

With the transition itself seen as costly and also feared to cause deterioration in welfare and other services, opponents also said the plan is a waste of money.

Matsui and Yoshimura were both first elected as governor and mayor respectively in November the same year on a platform to resurrect the metropolis plan.

In June 2017, a legal council was relaunched to map out the restructuring plan ahead of another referendum.