Horizon Space Acquisition I Corp., a Cayman Islands exempted company, has entered into a new financing agreement with Horizon Space Acquisition I Sponsor Corp., also a Cayman Islands company. On June 13, 2025, Horizon Space Acquisition I Corp. issued an unsecured promissory note worth $300,000 to its sponsor. The note, which carries no interest, is intended to provide general working capital as the company approaches its initial business combination. It is payable upon the consummation of the business combination or the expiry of the company's term, whichever comes first. Notably, the sponsor has the option to convert this note into private units of the company, including ordinary shares, warrants, and rights, under specified conditions. This arrangement is exempt from registration under the Securities Act of 1933.