Japan set to elect female prime minister in landmark first

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

In fact, a specialist likens taking up the nation's top job to taking a "poisoned chalice".

However, what is the reason does Japan frequently replace prime ministers? This is partly because of it being a "single-party system", explains Prof James Brown of Temple University in Japan.

The Liberal Democratic Party's control on the country's politics means the primary rivalry comes from inside the party, instead of from opposition groups.

"Therefore inside the LDP there are intense conflicts within various groups - they all want their own faction to get the leadership position."

"Thus although you could be chosen as prime minister, the moment you're in office, you have many individuals scheming to try to remove you again."

Key Factors Behind Frequent Changes

• One-party dominance restricts external competition
• Internal factional rivalries drive leadership contests
• The prime minister's position is often described as a "poisoned chalice"
• Government continuity stays difficult to achieve despite financial power