Up in the air, however, is whether the ruling bloc and its allies will keep the two-thirds "super majority" needed to begin the process of revising the constitution's pacifist Article 9 to further legitimize the military, a controversial step. Official results are not expected until Monday.
"Compared to other parties, the LDP feels more secure", she said.
Japanese are voting in an election for the upper house of parliament, where Prime Minister Shinzo Abe's ruling bloc is expected to keep the majority.
Gaining a two-thirds majority, however, would not ensure Abe's proposal to enshrine the military in the constitution would succeed, given differences among lawmakers on what exactly should be changed, political analysts noted. He wants to further legitimize the Japanese military - the Self-Defense Forces (SDF) - by altering Article 9, imposed by the occupying U.S. forces when the constitution was adopted in 1947.
The election was widely seen as make-or-break for Abe's longtime ambition to revise the postwar Constitution. In a July 13-15 poll from national broadcaster NHK, 29 percent of respondents said the constitution needed to be amended, 32 percent said it was not necessary to amend it, and 30 percent were undecided.
"We won more than half of the seats contested".More news: Man injured after vehicle drives through crowd at Irish cemetery
"Abe s strength is largely based on passive support resulting from disarray in the opposition camp and a lack of rivals", Shinichi Nishikawa, professor of political science at Meiji University in Tokyo, told AFP.
While stumping for LDP candidates in the lead-up to Sunday's vote, Abe, according to media reports, repeatedly stressed his promise to rewrite the supreme law, daring voters to choose between parties that "fulfill their responsibilities" to discuss its revision and those that don't.
The Japanese public remains divided about the constitutional revision. That would require a change in party rules. "I want to live up to the people's expectations".
"Foreign affairs will play an outsized role on Abe's agenda regardless of the outcome on Sunday, but especially if Abe fails to receive a pro-revision supermajority", Tobias Harris, an expert on Japanese politics at Teneo Intelligence, a consulting firm in Washington, said in an emailed newsletter.
Prime Minister Shinzo Abe, who is on the verge of securing his sixth successive national election victory, is expected to move forward on issues concerning the consumption tax rate hike and the amending of the Constitution.
Abe said resolving the decades-old issue of Japanese citizens abducted by North Korea and signing a peace treaty with Russian Federation would be his diplomatic priorities during the rest of his term.More news: Loki Disney+ Series Confirmed for Spring 2021 Release
His main campaign pitch centered on the "stability" of his government, a message he repeatedly referenced to evoke memories of chaos and high leadership turnover that pervaded the brief period in power of the Democratic Party of Japan.
Natsuo Yamaguchi, who heads the LDP's coalition partner Komeito, pledged to improve social security.
A voter who identified himself only as a company worker in his 40s said he chose a candidate and a party that have demonstrated an ability to get things done, suggesting he voted for Mr Abe's ruling party and its candidate, as "there is no point in casting my vote for a party or a politician who has no such abilities".
"I hope that the next ruling party and leaders will be able to take a solid look not only at Japan's domestic issues but also how Japan works with neighbouring countries", said Noriko Yasuhara, 63.
LDP Secretary-General Toshihiro Nikai told a TV broadcaster on Sunday that he'd support Abe if he wanted to seek a fourth term as ruling party president when his current tenure ends in September 2021.More news: SDCC 2019: Supergirl Season 5 Trailer