1. The plaintiff's appeal is dismissed.

2. The costs of appeal shall be borne by the Plaintiff.

The purport of the claim and appeal is the purport of the appeal.

Basic Facts

The Plaintiff entered into a construction contract with the Daejeon Regional Procurement Service (hereinafter referred to as the “instant construction project”) through the Daejeon Regional Procurement Service.

C A Co., Ltd. (hereinafter referred to as “C”) and D Co., Ltd. (hereinafter referred to as “D”) constituted a joint supply and demand organization (hereinafter referred to as “joint supply and demand organization”: C 55%, D 45%, and hereinafter referred to as “instant joint supply and demand organization”) and concluded a primary contract for construction works with the Plaintiff as the representative contractor C during the instant construction works. A, D, and E agreed to receive landscaping construction works among the instant construction works, and C, D, and E around December 4, 2013, the Plaintiff entered into the primary contract for construction works with the representative contractor C.

(All Shares: C 51.975%, D 42.5%, and E 5.5%) On March 23, 2017, the Plaintiff entered into five contracts with C, D, and E on March 23, 2017, with respect to the instant construction project, with the total amount of additional construction cost as KRW 13,072,66,00,50,550,526,000, and the date of completion as of March 22, 2018, with the representative contractor C, and the said five contracts were modified by three times until April 19, 2018.

(hereinafter “five-party contract”). The five-party contract was entered into in the form of an electronic contract, like the first contract for construction works entered into before, and at the time of entering into each of the above contracts, C, D, and Shared Supply and Demand Chain, a member of the instant joint contractor, submitted a “electronic contract undertaking” and included it in the contents of the above contracts.

Article 2 of the above "Rules of Joint Supply and Demand Agreements" shall substitute for the following contents, and it shall be deemed that the contents of the Joint Supply and Demand Agreement in force as of the date of conclusion of the contract shall be applied as they are, as they are, to the Rules of the Ministry of Public Administration and Security.

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5. The terms, such as the fifth contract.