The nation set to choose female prime minister in landmark first
Over the last two decades, the country has seen more than 10 prime ministers.
In fact, one expert likens taking up the nation's top job to drinking from a "cursed cup".
But why does the country frequently replace prime ministers? It's due in part 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 originates within the party, instead of from external parties.
"Therefore inside the LDP there are intense conflicts within different factions - they all want their own clique to get the top job."
"Thus although you could be chosen as leader, the moment you're in power, you have many individuals manoeuvring to try to get you out again."
Key Factors Behind Rapid Turnover
- Single-party rule limits outside challenges
- Party infighting drive power struggles
- The prime minister's position is frequently called a "poisoned chalice"
- Government continuity remains difficult to achieve despite financial power
