UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2023 Commission File Number 001-33098 Mizuho Financial Group, Inc. (Translation of registrant’s name into English) 5-5, Otemachi 1-chome Chiyoda-ku, Tokyo 100-8176 Japan (Address of principal executive office) Indicate by check mark whether the registrant files or will file annual reports under co ...