2020 Liberal Democratic Party (Japan) leadership election

The 2020 Liberal Democratic Party of Japan leadership election was held on 14 September 2020 to elect the next president of the Liberal Democratic Party of Japan, three days before the National Diet was scheduled to hold a session to elect the new Prime Minister. Initially scheduled to be held in September 2021, incumbent party president and the longest-serving Prime Minister of Japan, Shinzo Abe, suddenly resigned on 28 August 2020, citing recent health concerns, prompting an election to select the President to serve the rest of Abe's term. 
Chief Cabinet Secretary Yoshihide Suga easily won the election, securing endorsements from a majority of voting members of the party in the days preceding the vote. As the Liberal Democratic Party currently controls a majority in the National Diet as a member of the governing coalition, Suga successfully succeeded Abe as Japan's prime minister on 16 September 2020.
Background.
Following several hospital visits which launched speculation into his health, incumbent Prime Minister Shinzo Abe announced during a press conference on 28 August 2020 that he would resign before the end of his final term in office due to a resurgence of his chronic ulcerative colitis. During the press conference, Abe announced that as a result the LDP is preparing for a leadership election to choose his successor, and that he would not endorse any specific candidate.
Procedure.
There are two ways by which the president could be elected in the leadership election: the first would be an open election in which voting power is given to both party members and members of the National Diet. Each would receive half of the voting power to elect the new president. The other method would allow the vote to be restricted to the Diet members and representatives from each of Japan’s 47 prefectures, which would add up to 535 electors. According to an LDP lawmaker, Toshihiro Nikai, the party's secretary-general, decided on the second option. To appear on the ballot, candidates must receive at least 20 nominations from the 394 Diet members in the LDP caucus.