Yes, if you have borrowed 15,000 yuan and repaid more than 18,000 yuan, but still need to repay more than 9,000 yuan and have not repaid it for half a year, the following consequences may occur:

1. Overdue interest and late fees: Depending on the loan contract, late payments may incur additional interest and late fees. These fees increase the amount you need to repay.

2. Collection notices and phone calls: Creditors may contact you by phone, text message, or email to urge you to repay the debt as soon as possible. They have the right to take necessary legal action to recover the amount owed.

3. Bad credit record: Late repayments may cause damage to your credit record. This may affect your ability to apply for loans, credit cards or other credit products in the future.

4. Legal action: In some cases, creditors may take legal action and file a lawsuit in court to recover the amount owed. This may result in higher costs and inconvenience and may have a further negative impact on your financial situation.

Summary:

If you fail to repay the remaining 9,000 yuan within half a year, you may face increased overdue interest and late fees, harassment from collection notices and phone calls, and the impact of a bad credit record and possible legal action. It is recommended that you contact your creditor as soon as possible and seek suitable solutions, such as using family, friends or other lenders to pay off the debt, to avoid further consequences.