Japan set to choose female prime minister in historic first

Over the last two decades, the country has had over ten prime ministers.

In fact, a specialist compares assuming the nation's top job to taking a "cursed cup".

However, what is the reason does Japan keep changing leaders? This is partly because of it being a "single-party system", explains Prof James Brown of Temple University Japan.

The Liberal Democratic Party's control on the political landscape means the main political competition comes from inside the party, instead of from opposition groups.

"So within the LDP there are vicious struggles within different factions - they all want their own faction to secure the top job."

"So even though you could be selected as prime minister, as soon as you're in office, you have many individuals scheming to try to get you out again."

Main Reasons Behind Rapid Turnover

• Single-party rule restricts external competition
• Party infighting fuel power struggles
• The prime minister's position is frequently called a "cursed position"
• Government continuity remains difficult to achieve despite economic strength