Material event report (bonus issue)

What happened

Material Event Report / Exchange Reporting Duty Matter

To: Financial Services Commission / Korea Exchange July 7, 2026

Company name: Booster Co., Ltd. CEO: Yoo Seung-hyeop Head office address: 18 Godeung 2-gil, Iwol-myeon, Jincheon-gun, Chungcheongbuk-do Phone: 043-536-9107 Website: http://www.booster.co.kr Preparer: (Title) Managing Director (Name) Yoo Deok-gi (Phone) 043-536-9107

Bonus Issue Decision

1. Type and number of new shares: common shares 8,404,800; other shares - 2. Par value per share (KRW): 500 3. Total shares issued before the capital increase: common shares 8,404,800; other shares - 4. Record date for new share allotment: July 23, 2026 5. Number of new shares allotted per share: common shares 1; other shares - 6. Dividend record date for new shares: January 1, 2026 7. Expected date of delivery of new share certificates: - 8. Expected listing date of new shares: August 14, 2026 9. Board resolution date (decision date): July 7, 2026. Outside directors present: 1; absent: -. Attendance of auditor (audit committee member): present

10. Other matters for investors' reference a. Bonus issue allotment details: common shares before bonus issue 8,404,800; bonus issue allotment 8,404,800; after bonus issue 16,809,600 b. Method of allotting new shares and treatment of fractional shares: new shares will be allotted to shareholders registered in the shareholder register as of the record date (July 23, 2026) at a ratio of 1 new share per 1 share held; no fractional shares will arise. c. Amount to be capitalized and source of the new shares: share premium (capital surplus), KRW 4,202,400,000 d. Item 7, "Expected date of delivery of new share certificates," above is omitted as not applicable due to the implementation of the electronic securities system. e. Other incidental matters regarding the issuance of new shares are delegated to the CEO, and the above schedule may change through consultation with relevant institutions.

[Matters Concerning Other Shares] Basis in articles of incorporation: - Share terms: - Other: -