1. The plaintiff (Counterclaim defendant)'s main claim is dismissed.

2. The Plaintiff (Counterclaim Defendant) is entitled to KRW 96,260,417 against the Defendant (Counterclaim Plaintiff).

A principal lawsuit and counterclaim shall also be deemed a principal lawsuit and counterclaim.

1. Basic facts

A. On February 5, 2014, the Defendant (Counterclaim Plaintiff; hereinafter “Defendant”) and the Plaintiff (Counterclaim Defendant; hereinafter “Plaintiff”) concluded a contract with the Plaintiff (hereinafter “instant contract”) under which the construction cost of reinforced concrete construction works among the construction works of new apartment lots A and two parcels of land (hereinafter “instant construction works”) was KRW 935,000,000 (hereinafter “instant contract”).

B. On March 2014, the Plaintiff commenced the instant construction work from the first patrol officer.

However, on May 28, 2014, the Defendant notified the Plaintiff that the instant contract was terminated.

C. The Plaintiff filed an application with the competent court for the appraisal of the progress payment executed by the Plaintiff until the termination of the instant contract, and the appraiser of the instant case assessed the progress payment as KRW 246,979,000 as to the portion executed by the Plaintiff until the termination of the instant contract.

Before the termination of the instant contract, the Defendant paid the Plaintiff KRW 115,00,000 in total, and KRW 65,000 in total, and KRW 180,000 in total,00.

[Ground of recognition] Facts without dispute, Gap evidence 1, Gap evidence 4, Gap evidence 5, Eul evidence 11, the purport of the whole pleadings

2. Summary of the parties' arguments

A. The gist of the Plaintiff’s assertion 1) The Defendant shall pay the Plaintiff the remainder of KRW 66,979,000, excluding advance payment and progress payment, from the construction cost of KRW 246,979,000 for the instant construction cost. In addition, the Defendant paid the Plaintiff the amount of KRW 99,00,000, which was used by the Plaintiff until the completion of construction without returning it to the Plaintiff. As the Plaintiff paid the amount of KRW 99,00,000 for the mine pumps amounting to KRW 99,645, which was paid by the Plaintiff. 2) The Plaintiff shall return the remainder of the mine pumps amounting to the Defendant as unjust enrichment.