The House of Councilors election will be held within three months, and the focus is on whether the split in the Diet — where the two chambers of the legislature are controlled by different camps — will finally be mended.

The radical changes in global politics and economics are producing a wide range of potential campaign issues for Prime Minister Shinzo Abe. But he is likely to focus on three areas — economic policies to generate sustained growth in Japan after two "lost decades," participation in the Trans-Pacific Partnership talks, and constitutional revision — part of his Liberal Democratic Party's policy platform.

Prices on the Tokyo Stock Exchange, a leading indicator of the economy, are still rising under Bank of Japan Gov. Haruhiko Kuroda's shift in monetary policy from interest rates to liquidity.