The nation set to elect female prime minister in landmark first

In the past twenty years, the country has seen more than 10 leaders.

In fact, one expert likens taking up the country's top job to taking a "poisoned chalice".

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 LDP's grip on the country's politics means the primary rivalry originates inside the party, rather than from opposition groups.

"Therefore inside the LDP there are vicious struggles within various groups - they all want their own faction to get the top job."

"Thus although you might be chosen as leader, as soon as you're in power, you have dozens of people scheming to try to get you out again."

Key Factors Behind Frequent Changes

• Single-party rule restricts external competition
• Internal factional rivalries drive leadership contests
• The leadership role is often described as a "poisoned chalice"
• Political stability remains elusive despite financial power