House of Representatives member Yaichi Tanigawa, indicted over slush fund allegations involving the ruling Liberal Democratic Party's largest faction, resigned as a lawmaker on Wednesday.
North Korea has conducted a test of its underwater nuclear weapons system in a protest against the joint military drills by South Korea, the U.S. and Japan.
Around half of Japanese firms are reviewing or restructuring their businesses to boost corporate value amid a push for companies to improve governance.
Japanese Prime Minister Fumio Kishida has been compelled to rely more on former Prime Minister Taro Aso, called a "kingmaker" by critics, to maintain his administration amid a political fundraising scandal involving his Liberal Democratic Party.