The nation on course to choose woman prime minister in landmark first
Over the last two decades, the country has had more than 10 prime ministers.
Actually, a specialist likens taking up the nation's top job to drinking from a "poisoned chalice".
But why does Japan frequently replace prime ministers? This is partly because of it being a "single-party system", says Professor James Brown of Temple University Japan.
The Liberal Democratic Party's control on the political landscape means the main political competition originates within the party, instead of from external parties.
"So within the LDP there are intense conflicts within various groups - they all want their own clique to secure the top job."
"So even though 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 external competition
- Internal factional rivalries drive power struggles
- The leadership role is often described as a "poisoned chalice"
- Political stability stays elusive despite economic strength
