1. The plaintiff's appeal is dismissed.

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

The purport of the claim and appeal is the purport of the appeal.

1. Summary of the parties' assertion

A. (1) The Plaintiff’s assertion (1) around September 1, 2016, while running reinforced concrete construction (hereinafter “instant construction”) among the new construction works from around 1, 2016, the Plaintiff ordered the Defendant to order the cargo pumps necessary at the construction site of this case on October 18, 2016, and transferred KRW 1,8150,000 to the Defendant on November 1, 2016. However, the Defendant did not supply the cargo pumps at the construction site of this case, and the Defendant is obligated to return the said money to the Plaintiff.

(2) Preliminaryly, if the Plaintiff’s 1,8150,000 won paid to the Defendant does not have the right to pump, the Defendant shall return 1,8150,000 won to the Plaintiff as unjust enrichment on the ground that the Defendant gains profit from the Plaintiff’s property or labor without any legal ground and thereby causes loss to the Plaintiff.

B. It was true that the Defendant issued a tax invoice in the name of the Plaintiff and received KRW 18150,00 from the Plaintiff. However, Nonparty D, who traded with the Defendant, did not conclude a contract for the supply of uniforms with the Plaintiff, did not have any obligation to return the price to the Plaintiff to the Defendant, while working at the construction site of Nonparty E. In fact, Party F, a company, such as E, had a claim to G, and in fact, Company F, which was in fact, issued a tax invoice to receive the payment from the Plaintiff through a successive agreement between the Plaintiff and the Plaintiff, and Company C, E, G, and the Plaintiff issued the tax invoice to the Defendant to receive the payment from the Plaintiff.

2. Determination

A. The fact that the Plaintiff issued a tax invoice in the name of the Plaintiff as to the primary argument, and that the Plaintiff remitted KRW 8,150,000 to the Defendant on November 1, 2016 is deemed to have without dispute between the parties, and in light of the following circumstances revealed by the evidence submitted, including the entries in the evidence Nos. 3 and 4 and the testimony of the first instance witness G.