The nation set to choose woman prime minister in landmark first

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

Actually, a specialist compares taking up the nation's top job to taking a "poisoned chalice".

However, what is the reason does Japan keep changing leaders? It's due in part of it being a "one-party democracy", explains Professor James Brown of Temple University Japan.

The LDP's grip on the political landscape means the primary rivalry originates within the party, rather than from opposition groups.

"So within the LDP there are vicious struggles within various groups - they all desire their own faction to secure the top job."

"So even though you might be chosen as leader, the moment you're in office, you have dozens of people scheming to try to get you out again."

Main Reasons Behind Rapid Turnover

• One-party dominance restricts external competition
• Party infighting drive power struggles
• The prime minister's position is frequently called a "cursed position"
• Government continuity remains difficult to achieve despite financial power