1. The Defendant shall pay to the Plaintiff KRW 73,80,000 and the interest rate of KRW 12% per annum from November 15, 2019 to the date of full payment.

Comprehensively taking account of the overall purport of the arguments in Gap evidence Nos. 1 through 5, the plaintiff sold piping materials, etc. to non-party Co., Ltd. from June 30, 2019 to July 31, 2019, and C promised on August 29, 2019 that "93,80,000 won shall be paid until September 11, 2019" to the plaintiff, and the defendant may recognize the fact that the defendant guaranteed the above company's obligation to the plaintiff.

The plaintiff receives KRW 20,00,000 from the principal and appropriated it to the principal.

According to the above facts of recognition, the plaintiff may claim against the defendant the balance of KRW 73,800,000, except in extenuating circumstances.

Therefore, the Defendant is obligated to pay to the Plaintiff the amount of KRW 73,800,000 as the guarantee for the purchase price, and damages for delay at the rate of 12% per annum under the Act on Special Cases concerning Expedition, etc. of Legal Proceedings from November 15, 2019 (the day after the copy of the complaint of this case was served) to the day of full payment.

The plaintiff's claim is accepted and the decision is rendered in favor of the plaintiff.