Prime Minister Fumio Kishida and his Liberal Democratic Party are taking stock of what went wrong after a ruling bloc-backed candidate was defeated in an Upper House by-election on Sunday — just one week before the Oct. 31 general election.

Meanwhile, the Constitutional Democratic Party of Japan (CDP) and Democratic Party for the People (DPP) are hoping their candidate's victory in the Shizuoka by-election will provide a lift to their candidates next Sunday.

A separate by-election in Yamaguchi Prefecture brought some good news for the ruling coalition, however, with a candidate backed by the LDP and its partner Komeito recording a substantial victory over one supported by the Japanese Communist Party (JCP).