The ruling Liberal Democratic Party's presidential election will effectively be a vote to decide Japan's next prime minister as the LDP-led coalition holds a majority in both chambers of parliament, meaning whoever the party picks is almost certain to be elected the country's leader by the Diet.
To run in the leadership race, hopefuls are required to garner at least 20 nominations from among the LDP's Diet members.
Following campaigning, the election will be held with the LDP Diet members as well as rank-and-file members casting ballots and whoever secures a majority of votes will be declared the winner. If no candidate secures an outright majority in the first round, a runoff between the top two contenders will be held.
In the first round, each of the LDP's 383 Diet members will cast a vote and another 383 votes will be determined based on the preferences of rank-and-file members who are at least 20 years of age, hold Japanese nationality and have paid membership fees in the previous two years in principle.
In a runoff, the 383 Diet members and each of the LDP's 47 prefectural chapters will cast votes.