Notice Regarding the Resolution on Matters Concerning the Share Buyback and Share Cancellation (Share Buyback Based on the Provisions of Article 165, Paragraph 2 of the Companies Act, and Share Cancellation Based on the Provisions of Article 178 of the Companies Act)

Overview of Capital Policy

Mitsui Chemicals, Inc. has resolved to acquire and cancel treasury shares aiming to improve capital efficiency and enhance the effectiveness of shareholder returns. The target for acquisition is the company’s common shares, with an upper limit of 18,400,000 shares (approximately 4.9% of the total issued shares) and a maximum acquisition value of 30 billion yen. The acquisition period will be from February 6, 2026, to July 31, 2026, with shares to be purchased on the market. After acquisition completion, cancellation will be carried out so that the number of treasury shares held by the company is approximately 5% of the total issued shares, with the scheduled cancellation date being August 31, 2026.

Impact on Shareholders and Future Outlook

Through share buyback and cancellation, a decrease in the total number of issued shares is expected, which should enhance per-share value and improve capital efficiency. The specific number of shares acquired and cancelled will be announced after the acquisition is completed. As of January 31, 2026, the company holds 25,164,057 treasury shares, and this acquisition and cancellation are aimed at strengthening the effectiveness of shareholder returns.