1. Of the instant lawsuits, the part of the claim based on the subrogation right of the creditor is dismissed.

2. The plaintiff's remaining claims.

1. The parties' assertion

A. (1) The Plaintiff’s assertion (1) concluded a sales contract with Nonparty C, and the sales contract was rescinded, and Nonparty C returned KRW 30 million out of the sales price to the Defendant, one of the buyers under the contract.

However, the defendant is written as a purchaser in form, and there is no right to the purchase price.

Therefore, the plaintiff is entitled to exercise the subrogation right against the right to claim the return of unjust enrichment against the defendant by the non-party C as the right to claim the payment prohibition against the non-party C as the preserved right. Thus, the defendant must return the plaintiff KRW 30 million.

(2) In order to obtain a medical care center license, the Plaintiff paid KRW 10 million to the D organization represented by the Defendant in the form of a support payment. However, given that it is impossible to grant the current medical care center license, the Defendant, who received the above KRW 10 million, is obligated to return it as unjust enrichment.

B. The defendant's assertion (1) is merely a loan of KRW 30 million from the non-party C, not a refund of the money paid by the plaintiff in the name of the down payment.

(2) The Plaintiff did not pay KRW 10 million, and the parties to the support payment are not the Defendant, and the Plaintiff’s claim is unfair as it is a D organization that is not the Defendant.

2. Determination

A. Whether a creditor needs to preserve a claim as an exercise of a creditor's subrogation right against a claim of KRW 30 million should be determined at the time of the closing of pleadings in fact-finding proceedings. In a case where the claim is a monetary claim, if the debtor needs to prevent the reduction of general property due to his/her insolvency, it is permissible and the existence of such requirements should be asserted and proved by the creditor.

(see, e.g., Supreme Court Decision 75Da1086, Jul. 13, 1976). Based on the foregoing legal doctrine, the Plaintiff asserts in this part of the claim seeking reimbursement of unjust enrichment amounting to KRW 30 million by subrogation of C.