1. The plaintiff's claim is dismissed.

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

1. Basic facts

A. On November 9, 2015, the Defendant was awarded a contract for three main construction works, including urban gas admission, which takes place between November 13, 2015 and June 9, 2016, from the third joint venture of the Air Force, the total construction period of which is 49,590,060 won, and the construction period of which is 49,59,590,060 won, from the third joint venture of the Air Force located in Sindong-dong, Sin

B. On February 24, 2016, the Defendant issued a subcontract to the Plaintiff, setting the contract amount of KRW 151,800,000 (including value-added tax) for the urban gas pipeline construction (hereinafter “instant construction”) during the said construction period from February 11, 2016 to June 9, 2016, the advance payment of KRW 75,90,000, and the daily liquidated damages rate of KRW 1/1,000.

Then, on February 25, 2016, the Defendant paid KRW 75.9 million to the Plaintiff as advance payment.

C. The Plaintiff, around March 23, 2016, ordered the instant construction project subcontracted by the Defendant from the Defendant to the Sungsung T&C Co., Ltd., by setting the construction amount of KRW 145,728,00 (including value-added tax) and the construction period from March 23, 2016 to June 9, 2016.

On June 9, 2016, the scheduled date of completion of the instant construction works, the Plaintiff and Sungsung C&C Co., Ltd. filed an application for completion inspection with the Korea Urban Gas Corporation, but was judged inappropriate by the Korea Urban Gas Corporation.

On June 22, 2016, the Defendant notified the Plaintiff that the said subcontract will be terminated as of June 23, 2016.

E. As to the instant construction works, a completion inspection certificate was issued on August 29, 2016 from the Korea Urban Gas Safety Corporation.

[Ground of recognition] Unsatisfy, entry of Gap evidence 1 to 8, purport of whole pleadings

2. Judgment on the plaintiff's assertion

A. The plaintiff asserted that the construction work of this case was conducted at the defendant's request even after the decision of inappropriateness and the notice of termination of the construction contract was completed by the Korea Gas Safety Corporation.

Therefore, the Defendant is out of the remainder of the construction cost or the cost of the Plaintiff’s unjust enrichment of KRW 75.9 million (= contract amount of KRW 151,800,000 - advance payment of KRW 75.9 million).