1. The defendant's appeal is dismissed.

2. The costs of appeal shall be borne by the Defendant.

3. The judgment of the court of first instance is subject to Paragraph (1).

1. Facts of recognition;

A. The Plaintiff is a person operating a metal structure manufacturing and construction company, such as a Hand Hand, of the trade name “D,” and the Defendant is a company established for the purpose of the human body management construction business, etc., which is ordered to do the interior works of buildings for the purpose of E office at the time of strike (hereinafter “the interior works in this case”).

B. On January 26, 2018, the Plaintiff: (a) was commissioned by C with the name of “director of the Ministry of Construction and Transportation” of the Defendant; (b) the contract amount of KRW 10,450,00 (including value-added tax) for the interior Hand and railing (hereinafter “subcontract”); and (c) determined the contract amount of KRW 10,450,00 for the instant subcontracting work.

C. On January 26, 2018, the Plaintiff received KRW 4,000,000, out of the construction cost of the instant subcontract as a retainer, and the said amount was transferred from the Defendant’s account to the Plaintiff’s account.

After all, the subcontract price of this case was increased to KRW 10,670,000 (including value-added tax) due to the additional construction work.

E. On February 20, 2018, the Plaintiff completed the instant subcontract construction, and on March 2, 2018, filed a claim for the payment of the remaining construction cost by issuing an electronic tax invoice to the Defendant via C.

F. On April 11, 2018, C prepared a letter stating that “The Plaintiff shall pay KRW 6,670,000, which was not paid out of the construction cost of the instant subcontract, to the Plaintiff by June 25, 2018,” as the Defendant’s “director of the Ministry of Construction and Transportation.”

[Ground of recognition] Unsatisfy, entry of Gap evidence 1 to 5, purport of whole pleadings

2. Determination

A. According to the above facts of recognition as to the cause of claim, barring any special circumstance, the Defendant shall jointly and severally with C to the Plaintiff KRW 6,670,00 which was unpaid out of the construction price of the instant subcontract (= KRW 10,670,000 - KRW 4,00,000) and the following day after the date on which the Plaintiff requested the payment of the said construction price.