1. The defendant's appeal is dismissed.

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

Purport of claim and appeal

1...

1. In the first instance court, the Plaintiff filed a claim for monetary payment (the claimed amount of KRW 30,427,120 and delay damages therefrom) and a claim for restitution of unjust enrichment (the claimed amount of KRW 54,315,054 and delay damages thereon) with the Defendant under the panel agreement. The first instance court partly accepted the claim for monetary payment under the panel agreement and dismissed the claim for restitution of unjust enrichment in its entirety.

For this reason, the defendant only appealed against the cited part of the claim for monetary payment under the above panel agreement, so this court's decision is limited to the claim for monetary payment under the panel agreement partially accepted as above.

2. The reasoning of the court’s explanation concerning this case is as follows, except for the addition of the part concerning the defendant’s allegation of set-off by the court, and therefore, it is identical to the part concerning the reasoning of the judgment of the court of first instance pursuant to the main sentence of Article 420 of the Civil Procedure Act.

3. Judgment on the defendant's additional assertion

A. The Defendant’s defense of offset is gaining continuous profits from transactions with the Defendant’s book stores using the POS program for the sale of books after the termination of the “Contract to Use Credit Card Transaction Relay Services,” which was concluded with the Defendant.

The Plaintiff is obligated to return to the Defendant the amount equivalent to 11,01,105 won (i.e., the amount calculated as KRW 35 won per credit card transaction) earned without any legal cause by continuing transactions with the Defendant’s stores using the Defendant’s POS program during the period from June 10, 2015 to December 19, 2016, following the termination of the “credit card transaction relay service contract” as mentioned above (i.e., the amount calculated as KRW 35 won per case).

The Defendant shall set off against the Plaintiff the claim for return of unjust enrichment against the Defendant under the instant panel agreement against the Defendant by making the claim for return of unjust enrichment against the Defendant as an automatic claim.

B. We examine the judgment, and the plaintiff is the defendant.