A. The Defendant entered into a contract with the Korea Water Resources Corporation to enter into a contract with the Korea Water Resources Corporation for the construction period of C Corporation from March 30, 2015 to September 29, 2016, and KRW 4,962,870,000.

On August 30, 2016, the Defendant increased the contract amount to KRW 5,425,420,000 by reflecting any change in the design, such as the addition of a well-dying system, between the Korea Water Resources Corporation and the Korea Water Resources Corporation, and thereafter on November 30, 2016, the contract price was reduced to KRW 5,295,620,000.

B. On November 19, 2015, the Plaintiff entered into a subcontract between the Plaintiff and the Defendant with the terms that the Plaintiff was awarded a subcontract for the construction period of the said facilities from November 19, 2015 to August 13, 2016, and the construction cost of KRW 430,760,000, among the said facilities construction works. From November 19, 2015 to August 13, 2016, the Plaintiff entered into a subcontract for the construction period of the said facilities with the terms that the said construction of reinforced concrete was awarded a subcontract for the construction period of KRW 1,390,400,00 (only the part of the reinforced concrete construction in this case is problematic) (hereinafter referred to as the “instant construction”).

(2) On April 8, 2016, the Plaintiff and the Defendant concluded a contract to change the construction cost to KRW 1,470,000,000 with respect to the instant construction work.

3) On September 12, 2016, the Plaintiff and the Defendant agreed to increase the construction cost of the subcontract by reflecting any change in the design, such as adding a well-dying construction, etc., and accordingly, agreed to the following (hereinafter “instant agreement”).

(iii) the agreement has been concluded. The agreement has been amended.

1. The amount of the initial agreement of the instant construction is 1,429,00,000 won (including additional tax) including the types of work and the types of work in the maintenance and management room (such as steel framed construction, shipbuilding construction, roof and home line construction, metal construction, windows and glass construction, other construction, printing room construction, etc.) on the details of the subcontract reported, and the type of work (including 1,476,000 won) by design modification.