The nation set to choose female prime minister in landmark first

Over the last two decades, Japan has had over ten leaders.

Actually, a specialist compares assuming the country's top job to drinking from a "poisoned chalice".

However, what is the reason does the country frequently replace prime ministers? It's due in part of it being a "single-party system", says Prof James Brown of Temple University Japan.

The LDP's grip on the country's politics means the main political competition originates inside the party, instead of from opposition groups.

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

"Thus although you might be selected as prime minister, the moment you're in office, you have many individuals manoeuvring to try to remove you again."

Main Reasons Behind Frequent Changes

• Single-party rule limits external competition
• Internal factional rivalries fuel power struggles
• The leadership role is frequently called a "cursed position"
• Government continuity remains difficult to achieve despite financial power