The nation set to elect female prime minister in historic first

In the past twenty years, Japan has had over ten prime ministers.

In fact, a specialist compares taking up the country's top job to drinking from a "poisoned chalice".

But why does Japan frequently replace prime ministers? This is partly because of it being a "one-party democracy", says Prof James Brown of Temple University Japan.

The LDP's grip on the political landscape means the primary rivalry comes from within the party, instead of from opposition groups.

"So within the LDP there are intense conflicts within various groups - they all want their own clique to get the top job."

"So even though you could be chosen as prime minister, as soon as you're in office, you have dozens of people manoeuvring to try to remove you again."

Main Reasons Behind Rapid Turnover

• Single-party rule restricts outside challenges
• Internal factional rivalries fuel power struggles
• The leadership role is often described as a "cursed position"
• Political stability stays difficult to achieve despite economic strength