1. The plaintiff's claim is dismissed.

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

1. Basic facts

A. On April 2015, the Plaintiff entered into a subcontract with C Co., Ltd. (hereinafter in the name of all companies omitted) and D Co., Ltd. with respect to electrical construction (hereinafter “D Co., Ltd.”), with the construction cost of KRW 380 million (excluding value-added tax).

B. On April 14, 2015, the Plaintiff calculated C’s progress rate of construction up to 19%, 79,689,390 won for progress (including value-added tax) and agreed upon C’s completion amount of construction work as KRW 77 million (including value-added tax).

C. On May 1, 2015, the Plaintiff concluded a new subcontract with the Defendant for electrical construction (hereinafter “instant contract”) with the period from May 1, 2015 to August 30, 2015, for the construction cost of KRW 250 million (excluding value-added tax) and for the construction period (hereinafter “instant contract”).

[Grounds for recognition] The descriptions of evidence Nos. 1 and 5, and the purport of the whole pleadings

2. The plaintiff's assertion and judgment

A. The Plaintiff asserted that C shall include the progress payment of KRW 77 million which it performed with the Defendant in determining the construction price in the course of entering into the instant contract with the Defendant. However, the Plaintiff shall pay only KRW 173 million after deducting KRW 77 million from the construction price of KRW 250,000,000, which is KRW 777,000,000, and paid KRW 251,818,181 (excluding value-added tax) to the Defendant. Thus, the Defendant is obligated to return the difference to the Plaintiff as unjust enrichment.

B. The Plaintiff asserted that E, the Defendant’s agent, included the construction cost of KRW 150,00,000 under the instant contract as KRW 250,000,000,000,000 for the completion payment of KRW 77,000,000,000, and determined the construction cost of the instant contract. The Plaintiff asserted that, as evidence corresponding thereto, there was evidence No. 4-1 and No. 2-2, and witness F’s testimony; however, the construction cost determined by the Plaintiff with C was KRW 380,00,000,000 for the payment of KRW 70,000 from the said construction cost (excluding value added tax) and material cost of KRW 4.