1. The Defendant’s KRW 54,049,01 as well as the Plaintiff’s KRW 6% per annum from November 14, 2009 to February 12, 2015, and the following.

1. Basic facts

A. On April 10, 2009, the Plaintiff operated an individual company with the trade name of “B,” and entered into a supply contract (hereinafter “instant supply contract”) with the Defendant and the delivery date from April 20, 2009 to July 31, 2009, setting the contract amount as KRW 885,49,842 (including value-added tax) with respect to the supply of the other day at the apartment site of “B” (hereinafter “the instant construction site”). The price for the import contract is calculated as KRW 1,400 (the time of remittance) and the actual settlement of the price is determined by applying the exchange rate standard (the time of delivery) on the date of remittance for B/L payment (the date of delivery).

B. In addition, at the time of the instant supply contract, L/C payment (20% of the import price), B/L payment (50% of the import price), on-site arrival (30% of the import price), and balance (30 days after domestic delivery) were paid in installments.

C. The Plaintiff supplied a different date to the construction site of this case pursuant to the supply contract of this case. The Plaintiff issued a tax invoice as listed below with respect to the amount including the additional quantity, and claimed payment thereof to the Defendant. The Plaintiff received a total of KRW 892,68,542 from the Defendant, as indicated below, as the price under the supply contract of this case.

The amount paid by Defendant 1 on April 20, 209 as of the aggregate of the tax invoices issued on the tax invoices of 157,935,530 won on April 20, 209, April 157, 2009,935,530 won on April 24, 2009, 394,838,400 won on April 24, 2009, 36. 7. 10,000,000 won on May 20, 2009, 7. 7. 10,000,000 won on May 20, 2006, 7. 7. 10,000 won on May 31, 200, 2007; 9. 10,000 won on May 31, 200, 2009; 9. 38,000 won on June 30, 209, 209.

D. Meanwhile, on the other hand.