1. The plaintiffs' claims are dismissed.

2. The costs of lawsuit are assessed against the plaintiffs.

1. Basic facts

A. In July 2017, the Defendant announced a bid for the procurement commodities to purchase the lux belt or 24,170 blives of estimated prices of KRW 679,863,482.

B. On August 10, 2007, Plaintiff B participated in the tender and was awarded a successful bid in KRW 617,29,990, and entered into a purchase contract with the Defendant to supply goods to the Defendant on September 30, 2007 with the delivery deadline.

(hereinafter “instant contract”). In order to guarantee the performance of the instant contract, Plaintiff B submitted to the Defendant a guarantee creditor the guarantee creditor amount of the Defendant, the guarantee amount of the Seoul Guarantee Insurance Co., Ltd., which is KRW 61,729,99.

C. The Defendant urged the Plaintiff B to implement the instant contract four times from October 30, 2007 to November 29, 2007, but the Plaintiff failed to perform this, thereby cancelling the instant contract on December 6, 2007.

The defendant received 61,729,990 won of the performance bond of the contract of this case from the Seoul Guarantee Insurance on March 10, 2008.

[Ground of recognition] Evidence Nos. 1 through 6, Evidence Nos. 1 and 2, and the purport of the whole pleadings

2. The plaintiff's assertion that the defendant should provide the plaintiffs with government-funded materials and advance payment.

The contract of this case was rescinded without fulfilling these obligations.

A reasonable performance guarantee shall be claimed as the return of unjust enrichment.

3. If the purport of the entire argument is added to the evidence Nos. 2 and 12 of the judgment, the defendant can recognize the fact that the contract of this case was concluded by setting the contract amount as the contract amount of KRW 617,29,99,90, and the payment method of KRW 619

There is no evidence to prove that the Defendant agreed to supply raw materials or advance payment to the Plaintiff B.

In addition, there is no relationship between the plaintiff A and the defendant.

A right to the State, which has not been exercised for five years, shall lapse by prescription, if it has not been exercised for any payment of money.

(Article 96(2) of the National Finance Act. The plaintiffs have reverted the contract bond to the National Treasury on March 10, 2008.