6-K

No.1-7628

SECURITIES AND EXCHANGECOMMISSION

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 DECEMBER 2025

COMMISSION FILE NUMBER: 1-07628

HONDA GIKEN KOGYO KABUSHIKI KAISHA

(Name of registrant)

HONDAMOTOR CO., LTD.

(Translation of registrant’s name into English)

2-3, Toranomon 2-chome,Minato-ku, Tokyo 105-8404, Japan

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F  *  Form 40-F

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):

Contents

Exhibit 1:

Notice Concerning Equity-Method Affiliates (Transfer to Consolidated Subsidiary)

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: December 16, 2025

[Translation]

December 16, 2025

Toshihiro Mibe

Director, President and Representative Executive Officer

(Securities Code: 7267 Prime Market, TSE)

Head of Accounting and Finance Unit

(TEL: +81-3-3423-1111)

Notice Concerning Equity-Method Affiliates (Transfer to Consolidated Subsidiary)

Honda Motor Co., Ltd. (the “Company”) has resolved to acquire an additional 21% equity interest in Astemo, Ltd. (“Astemo”), an equity-method affiliate, from Hitachi, Ltd. (“Hitachi”) and to make Astemo a consolidated subsidiary, as outlined below.

In January 2021, Astemo (formerly Hitachi Astemo) was formed through the management integration of four companies, namely Hitachi Automotive Systems, Ltd., and three Honda subsidiaries, Keihin Corporation, Showa Corporation and Nissin Kogyo Co., Ltd.

In October 2023, by welcoming JIC Capital, Ltd. (“JICC”, including JICC-01 Limited Partnership managed by JICC-01 G.K., which is a wholly owned subsidiary of JICC) as a new joint partner, the shareholding structure was changed to the current arrangements: 40% for Honda, 40% for Hitachi, and 20% for JICC. By leveraging its strong software development capabilities and accelerating investment in advanced technology areas, Astemo has been striving to achieve sustainable growth and solidify its position as a global mega supplier.

In the interim, the environment surrounding the automotive industry is constantly changing. In particular, it is expected that the industry will continue to see an accelerated shift toward software-defined vehicles (SDVs) — where the value of mobility products is defined more by software technologies that enhance the functionality of vehicles through autonomous driving and over-the-air updates, rather than primarily hardware technologies. In light of this trend, Honda will continue to enhance its SDV development capabilities and cost competitiveness with an even greater sense of urgency.

Astemo has strengths in both hardware and software technologies and will continue to be an important partner for Honda, and the growth of Astemo is indispensable for Honda to enhance its SDV development capabilities and cost competitiveness. In the face of the rapid and intense changes in the automotive business environment, as a parent company, it is essential for Honda to lead the transformation of Astemo so that Astemo can pursue the establishment of a business structure that enables high-speed, high-efficiency development of AI and software technologies, which will become increasingly necessary in the era of SDVs.

Based on this belief, Honda, Hitachi and JICC have agreed that Honda will acquire additional shares of Astemo, equivalent to 21% of all outstanding shares, from Hitachi, thereby changing the shareholding structure to 61% for Honda, 19% for Hitachi, and 20% for JICC.

As a parent company, Honda will lead the growth of Astemo as a global supplier, while maintaining the consideration of an IPO.

All values are in Japanese Yen.

The impact of this transaction on the Company’s consolidated operating results and financial position is currently under review. The Company will promptly notify of any matters that need to be announced in the future.