1. The plaintiff's appeal is dismissed.

2. Upon the plaintiff's conjunctive claim added by this court, the defendant.

1. Facts of recognition;

A. Upon receipt of orders from B, the Plaintiff supplied ready-mixeds equivalent to KRW 9,516,100 in total at the construction site of electric power resource housing located in Ischeon-si C eight times from October 13, 201 to November 26, 201.

B. The Plaintiff requested data on the issuance of the tax invoice to B prior to the supply of ready-mixed. At the time, B obtained the Defendant’s representative director’s permission and provided the Plaintiff with information, such as the Defendant’s business registration certificate and e-mail and facsimile number. Accordingly, at the time, the Plaintiff was aware of B’s employee

C. The Plaintiff issued electronic tax invoices to the Defendant as a recipient of the data received from B, and the Defendant approved them, and thereafter received KRW 4,00,000, out of the above ready-mixed amount from B.

[Ground of recognition] Facts without dispute, Gap evidence 1, Gap evidence 2-1, Gap evidence 2-2, Gap evidence 3, Eul witness Eul's testimony, witness Eul's witness Eul's witness's witness's testimony, the purport of the whole pleadings

2. The plaintiff's assertion and judgment

A. The Plaintiff’s assertion (1) is primarily based on the following: (a) the Plaintiff entered into a contract for the supply of ready-mixed with the Defendant and supplied ready-mixed, but failed to receive KRW 5,516,100 ( KRW 9,516,100 - KRW 4,000), and thus, sought payment.

(2) Preliminaryly, the Defendant is obligated to pay KRW 5,516,100 to the Plaintiff who supplied ready-mixed by mistake as the opposite contractual party, as the Defendant allowed the Plaintiff to be supplied with ready-mixed by using the Defendant’s trade name by issuing the business registration certificate to B.

B. (1) According to the above facts of recognition and each of the above evidence as to the main claim, the actual owner supplied with ready-mixed by the plaintiff is B, and at the time the construction work performed independently by the defendant regardless of the defendant. However, the defendant can be acknowledged that the defendant only allowed B to use the defendant's trade name when it is supplied with ready-mixed by the plaintiff, and there is no counter-proof.