According to the above facts, it can be recognized that the plaintiff lent KRW 100 million to the defendant on August 20, 2010 as the due date for repayment on October 20, 2010. Thus, the defendant is obligated to pay to the plaintiff damages for delay calculated at the rate of KRW 100 million and 5% per annum as stipulated in the Civil Act from October 21, 2010 to March 29, 2017, the delivery date of the original copy of the payment order in this case, and 15% per annum as stipulated in the Act on Special Cases Concerning the Promotion, etc. of Legal Proceedings from the next day to the date of full payment.

2. Judgment on the defendant's assertion

A. The Defendant asserts that the Plaintiff did not borrow KRW 100 million from the Plaintiff. As long as the establishment of a disposal document is recognized as authentic, the court shall recognize the existence and content of the declaration of intent in accordance with the language and text stated in the disposal document unless there is any clear and acceptable counter-proof as to the denial of the contents stated in the disposal document (see, e.g., Supreme Court Decision 2015Da256732, Jun. 9, 2016). Since there is no counter-proof to deny the contents of the above loan certificate, the Defendant’s above assertion is without merit.

B. The defendant asserts that the above loan certificate was made by the plaintiff's duress and thus it is not effective. However, there is no evidence to acknowledge the plaintiff's duress, and the defendant's above assertion is without merit.

3. In conclusion, the plaintiff's claim is reasonable, and it is so decided as per Disposition.