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

What happened

MATERIAL EVENT REPORT / Matters subject to stock exchange reporting duty To: Financial Services Commission / Korea Exchange August 13, 2026

Company name: Koas Co., Ltd. CEO: Noh Byeong-gu Head office address: 17 Seonyu-ro 52-gil, Yeongdeungpo-gu, Seoul (Dangsan-dong 6-ga) (Phone) 02-2163-6000 (Website) http://www.ikoas.com Preparer: (Title) Executive Director (Name) Jang Hyeong-gi (Phone) 02-2163-6000

Decision to acquire own convertible bonds before maturity

1. Type of bond Series: 5 Type: Unregistered, coupon-bearing, unsecured, privately placed convertible bonds

2. Bond issue date: 2024-09-11 3. Bond issuance method: Private placement 4. Bond maturity date: 2027-09-11 5. Total face value (electronically registered) of the bonds (KRW): 150,000,000 6. Face value (electronically registered) amount of bonds subject to acquisition (KRW): 150,000,000 7. Acquisition decision date: 2026-08-13 8. Acquisition amount Amount (KRW): 150,000,000 Basis for calculation: principal and interest payment (scheduled) date: 2026-09-11 Source of acquisition funds: Own funds 9. Acquisition method: Over-the-counter purchase 10. Reason for acquisition before maturity: Exercise of bondholder's early redemption request (put option) 11. Future handling plan: Scheduled for retirement after acquisition 12. Matters related to conversion Conversion ratio (%): 100 Conversion price as of report date (KRW/share): 2,994 Type of shares to be issued upon conversion: Common shares Number of shares: 50,100 As % of total shares: 0.35 Conversion request period - Start date: 2025-09-11; End date: 2027-08-11 13. Remaining face value (electronically registered) of bonds after acquisition (KRW): - 14. Whether subject to Fair Trade Commission filing: Not applicable 15. Other matters for reference in investment decisions - The above "7. Acquisition decision date" is the date internal approval for this bond acquisition was completed. - Details related to the 5th series convertible bonds are as follows: 1) Total issued amount: KRW 10,000,000,000 2-1) Total amount already converted: KRW 9,350,000,000 2-2) Total amount already acquired (retired): KRW 500,000,000 3) Balance before this acquisition: KRW 150,000,000 4) Total amount to be acquired this time: KRW 150,000,000 5) Balance after acquisition: KRW 0 - The "shares to be issued upon conversion" in "12. Matters related to conversion" above is the number of shares and the ratio to total shares that would be issued if the convertible bonds acquired this time were converted; the portion of convertible bonds acquired this time will not be converted but will instead be retired.

[Matters related to the seller] Seller name: - Relationship with the company or largest shareholder: - Basis for selection: Bondholder Transaction history and plans within 6 months before/after the acquisition decision: - Face value of bonds sold (KRW): 150,000,000 Remarks: -