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

2. The costs of appeal are assessed against the Defendant-Counterclaim Plaintiff.

purport, purport, and.

A principal lawsuit and a counterclaim shall also be deemed to have been filed.

1. Facts of recognition;

A. On December 4, 2014, the Defendant contracted the C-Ground Housing Construction to B on December 4, 2014.

B. Upon receiving an order from B on January 9, 2015, the Plaintiff supplied ready-mixeds equivalent to KRW 4,940,000 at the said construction site.

C. On January 16, 2015, B became unable to carry out construction due to nonperformance.

Accordingly, according to the Defendant’s order, not B, the Plaintiff supplied ready-mixeds equivalent to KRW 3,572,00 on January 30, 2015, and KRW 3,801,60 on March 10, 2015.

The Defendant remitted to the Plaintiff KRW 3,525,00 on January 31, 2015, and KRW 4,940,00 on March 7, 2015, respectively.

[Reasons for Recognition] Unsatisfy, Gap 1-4 evidence, Eul 1-2 evidence (including provisional number), the purport of the whole pleadings

2. The parties' assertion

A. The Defendant’s transfer of KRW 4,940,00 to March 7, 2015 is the supply price for ready-mixed as of January 9, 2015.

Since the defendant did not pay 3,801,600 won for the supply of ready-mixed on March 10, 2015, the defendant is obligated to pay the above payment to the plaintiff.

B. The Defendant remitted KRW 4,940,000, which was remitted on March 7, 2015, to Defendant in advance for the supply of ready-mixed on March 10, 2015.

The Plaintiff shall return KRW 1,138,400 (=4,940,000-3,801,600), which is the difference between the amount remitted in advance to the Defendant and the actual amount of supply.

Since the defendant paid all the related construction cost to B, the plaintiff must claim the supply price of ready-mixed on January 9, 2015 to B.

3. Determination

A. According to the above evidence and the following circumstances, the Defendant’s 4,940,000 won remitted on March 7, 2015 is the supply price of ready-mixed as of January 9, 2015, and the Defendant did not pay the supply price of ready-mixed as of March 10, 2015.

The defendant's assertion of repayment and return of unjust enrichment is without merit.

(1) The defendant and B shall determine the unit cost, period, products, and materials for each process in consultation between the project owner and the contractor, and shall include ready-mixed, steel bars, etc.