Shigeru Ishiba is set to become Japan's next prime minister after winning ruling party leadership election

Former defense minister Shigeru Ishiba has won his fifth bid to become the leader of Japan's ruling party on Friday, lining him up to become the country's next prime minister.

Ishiba defeated economic security minister Sanae Takaichi, who was vying to become Japan's first female prime minister, in a runoff after the two won the most votes in the first round in a crowded field of nine candidates.

The 67-year-old veteran politician will succeed outgoing Prime Minister Fumio Kishida, who threw the Liberal Democratic Party for a loop when he announced in August that he would not be running for its top office, effectively ending his three-year term. 

Ishiba is now expected to be approved as prime minister in a vote by parliament on Oct. 1 due to the LDP having a majority in both chambers of the legislature, effectively ensuring its chief becomes the next prime minister.

The election outcome is set to have major implications for Japan, with Ishiba inheriting a party marked by a corruption scandal, an economy in a precarious transition from years of stagnation, and emerging security and diplomatic threats on the world stage.

In the run up to the election, Ishiba endorsed the Bank of Japan's policy of steadily raising interest rates and voiced concerns about depreciation of the yen, differentiating himself from runoff opponent Takaichi who supported ultra-low-rates.

In March, the Bank of Japan exited a policy of long-held negative interest rates and then raised rates again in July. Ishiba had been a critic of the BOJ's negative interest rates policies under former premier Shinzo Abe's "Abenomics" policies.

In his past runs against Abe, the lawmaker had also centered rural revitalization policies, as Japan's countryside suffers from the