The plaintiff's appeal and the conjunctive claim added in the trial are all dismissed.

costs of lawsuit after an appeal are filed.

1. The reasoning of the court's explanation of this case is as stated in the reasoning of the judgment of the first instance, except for adding the judgment as described in the following Paragraph 2 to the conjunctive claims added by the plaintiff in the trial, and therefore, it is acceptable to accept this as it is in accordance with the main sentence of Article 420 of the Civil Procedure Act.

2. The decision on additional claims (the decision on the preliminary claims)

A. The gist of the plaintiff's conjunctive assertion was that the plaintiff paid KRW 212,200,00 to the defendant, and only KRW 55,00,000 to the defendant was refunded. If the loan was not acknowledged between the plaintiff and the defendant, the amount that the defendant received from the plaintiff was obtained without any legal ground. Thus, the defendant must return the difference of the above amount to the plaintiff as unjust enrichment.

B. Specific determination 1) The burden of proving that there is no legal basis in the case of so-called unjust enrichment for benefit, one of the parties who made a certain benefit at his/her own will and demanded the return of the benefit on the ground that the benefit was not legally attributable. In such cases, the party who seeks the return of unjust enrichment must assert and prove together with the existence of the fact causing the act of payment, as well as the existence of the fact that the cause was extinguished due to invalidation, cancellation, cancellation, etc., and in the case where the so-called unjust enrichment is the same as the so-called wrongful remittance for the reason that there was no cause causing the act of payment, the party who sought the return of unjust enrichment must prove and prove that he/she remitted the benefit by mistake. This is distinguishable from the one who proves that the other party to the claim for return of unjust enrichment has a legitimate right to hold the benefit (see Supreme Court Decision 2017Da37324, Jan. 24, 2018).