Shigeru Ishiba was elected as the new prime minister of Japan on Friday. The country’s governing political party, the Liberal Democratic Party, voted for the former minister of defense to lead the country.

Japan’s benchmark Nikkei 225 index tumbled nearly 5% early Monday after the country’s ruling Liberal Democrats chose Shigeru Ishiba, a former defense minister, as the next prime minister.

At least that is the case for Ishiba Shigeru, a maverick from Japan’s ruling Liberal Democratic Party (LDP). He defeated eight colleagues to win his fifth bid for party leadership on September 27th. This means he will become Japan’s prime minister when he is sworn in next week.