1. Revocation of a judgment of the first instance;

2. The plaintiff's claim is dismissed.

3. All costs of the lawsuit shall be borne by the Plaintiff.

1. The following facts do not conflict between the parties, or can be acknowledged in full view of Gap evidence No. 1, Gap evidence No. 2, Gap evidence No. 3, Eul evidence No. 4, Eul evidence No. 1, Eul evidence No. 2, and Eul evidence No. 3, and the whole purport of the arguments No. 3.

From March 2017 to April 2018, Nonparty C supplied goods of KRW 201,004,430 to the Defendant.

B. On August 24, 2018, Nonparty C transferred to the Plaintiff the claim amounting to KRW 53,923,890 among the above product price claim against the Defendant.

C. On September 5, 2018, Nonparty C notified the Defendant of the assignment of claims, and the notification of the said assignment of claims reached the Defendant on September 6, 2018.

From March 20, 2017 to April 16, 2018, the Defendant paid KRW 227,880,540 to Nonparty C.

2. Determination

A. According to the above facts of recognition as to the cause of the claim, the defendant is obligated to pay the plaintiff the claim for the price of the goods taken over from Nonparty C, unless there are special circumstances to the plaintiff.

B. The defendant's defense is proved that the defendant paid all the price of the goods to the non-party C before the non-party C transferred the claim for the price of the goods in this case to the plaintiff.

According to the above facts, the defendant transferred the claim for the price of the goods of this case to the plaintiff, and fully repaid the claim for the price of the goods of this case before the notification of the assignment of claims reaches the defendant, and can be set up against the plaintiff, the assignee of the claim before receiving the notification of assignment as above pursuant to Article 451 (2) of the Civil Act. Thus, the plaintiff's claim for the price of the goods of this case taken over from the non-party C was extinguished due to the defendant's repayment. Thus, the defendant's defense

C. If so, the plaintiff's assertion that the defendant is liable to pay the price of the goods of this case is without merit.

3. Accordingly, the Plaintiff’s claim of this case is groundless.