All appeals are dismissed.

The costs of appeal are assessed against the Defendant (Counterclaim Plaintiff).

1. As to the ground of appeal No. 1, the court below held that the Seoul Guarantee Insurance Co., Ltd. (hereinafter only referred to as the "Seoul Guarantee Insurance") paid to the Defendant (Counterclaim Plaintiff; hereinafter referred to as the "Defendant") a performance bond under the agreement of the Plaintiffs except for the Plaintiff (Counterclaim Defendant), and received reimbursement from the above Plaintiffs. However, after the Seoul Guarantee Insurance was filed the principal lawsuit in this case and notified the Defendant in writing that "if unjust enrichment is confirmed according to the result of the principal lawsuit in this case, it should be returned," and the above Plaintiffs paid the guaranteed insurance money. The court below prepared a confirmation document that "the liability to return the result of the lawsuit in this case becomes final and conclusive," and received the reimbursement from the above Plaintiffs, taking into account the provisional nature of the payment of the guaranteed insurance money and the payment of the reimbursement amount, the attitude and position of the Seoul Guarantee Insurance Co., Ltd., and the most effective method to resolve uncertainty in the existing legal relationship between the above Plaintiffs, Defendant, and Seoul Guarantee Insurance Co., Ltd., the core method to confirm the absence of the above Plaintiffs' interest in this case.

In addition, Article 1 of the Agreement provides that the performance guarantee bond shall belong to the defendant and in this case the plaintiffs shall not be subject to any lawsuit, etc. that interferes with the aforementioned attribution. Thus, the dispute, the lawsuit of which is prohibited pursuant to the above Article 24 (2) and (3) of the Agreement, "the failure to conclude a contract for the transfer of land and the loss of profits from the loan," shall be subject to the grounds not falling under any subparagraph of Article 24 (2) and (3) of the Business Convention.