Material event report (decision to redeem own convertible bonds early)

What happened

Koas Co., Ltd. Material event report / Matter subject to KRX reporting obligation To: Financial Services Commission / Korea Exchange August 19, 2026 Company name: Koas Co., Ltd. CEO: Noh Byeong-gu Head office location: 17 Seonyu-ro 52-gil, Yeongdeungpo-gu, Seoul (Dangsan-dong 6-ga) Phone: 02-2163-6000 Website: http://www.ikoas.com Preparer: (Title) Managing Director (Name) Jang Hyeong-gi (Phone) 02-2163-6000

Decision to redeem own convertible bonds before maturity 1. Type of bond: Series 7, unregistered, interest-bearing, unsecured, privately placed convertible bond 2. Bond issuance date: September 11, 2024 3. Bond issuance method: Private placement 4. Bond maturity date: September 11, 2027 5. Total face (electronically registered) amount of bond (KRW): 405,283,000 6. Face (electronically registered) amount of bond subject to acquisition (KRW): 5,283,000 7. Date of acquisition decision: August 19, 2026 8. Acquisition amount: amount (KRW) 5,283,000; basis of calculation: principal and interest; (expected) payment date: August 19, 2026; source of acquisition funds: own funds 9. Acquisition method: Over-the-counter purchase 10. Reason for acquisition before maturity: Agreement with bondholder 11. Future handling plan: To be retired after acquisition 12. Conversion-related matters: Conversion ratio (%): 100; Conversion price as of reporting date (KRW/share): 2,994; Type of stock to be issued upon conversion: common stock; Number of shares: 1,765; Ratio to total shares outstanding (%): 0.01; Conversion request period: start September 11, 2025; end August 11, 2027 13. Remaining face (electronically registered) balance of bond after acquisition (KRW): 400,000,000 14. Subject to Fair Trade Commission reporting: Not applicable 15. Other matters for investment reference: - "7. Date of acquisition decision" above is the date internal approval for this bond acquisition was completed. - Details of the Series 7 convertible bond: 1) total issuance amount: KRW 10,000,000,000; 2-1) total amount already converted: KRW 9,414,717,000; 2-2) total amount already acquired (retired): KRW 180,000,000; 3) balance before this acquisition: KRW 405,283,000; 4) amount to be acquired this time: KRW 5,283,000; 5) balance after acquisition: KRW 400,000,000. - The "shares to be issued upon conversion" under "12. Conversion-related matters" is the number of shares and ratio to total shares that would be issued if the bond acquired this time were converted; however, the bond acquired this time will be retired rather than converted.

[Matters concerning the seller] Seller name | Relationship with company or largest shareholder | Selection background | Transactions/plans within 6 months before/after acquisition decision | Face amount of bond sold (KRW) | Note Kim Hyeon-su: -; Bondholder of this bond; -; 5,283,000; -