1. Of the judgment of the court of first instance, KRW 1,078,663,397 against the Plaintiff and its related thereto from July 1, 2010 to September 20, 2012.

1. The reasoning of this court concerning this part of the basic facts is the same as the corresponding part of the judgment of the court of first instance, and thus, they are cited by the main sentence of Article 420 of the Civil Procedure Act.

2. Determination as to the cause of action

A. Since the Plaintiff’s assertion is likely to conflict with the prohibition clause of sub-subcontracts under the Framework Act on the Construction Industry, GS Construction entered into a modified contract with the Defendant to directly subcontract the instant contract to the Defendant, and accordingly agreed that the instant contract shall be retroactively null and void, the Defendant is obligated to return to the Plaintiff the price received as advance payment and payment for completed portion in accordance with the instant contract. Even if the instant contract was not retroactively null and void, all part of the exhibition facilities in B district that the Plaintiff contracted from GS Construction was contracted from GS Construction was agreed between the Defendant and the Defendant to rescind or terminate the instant contract, and thus, the Defendant is obligated to return the price received as advance payment and payment for completed portion.

B. In full view of the following facts: (a) the fact that the construction entered into a modified contract with the Plaintiff for each of the existing supply contracts with the Plaintiff and the Defendant, and the Plaintiff entered into a modified contract with the Defendant to directly subcontract part of the facilities located in the facilities located in the Class B, and accordingly adjusted each contract amount; and (b) each of the above written evidence Nos. 6 through 10, Nos. 4 through 8, and 10 (including each number; hereinafter the same shall apply); (c) the witness D, G, and witness E of the first instance court; and (d) the testimony of the first instance court and the first instance court and the party members GS construction or the fact-finding each of the results of each fact-finding agreements with the Plaintiff, the GS construction re-subcontracted the facilities located in the Class B in the subcontract between the Plaintiff and the Plaintiff to the Defendant.