1. The part concerning the claim for return of unjust enrichment in the instant lawsuit is dismissed.

2. The plaintiff's remaining claims are dismissed.

3...

1. Basic facts

A. The Plaintiff, a company running the insurance business, is an insurer who entered into a contract with 78 patients listed in the attached Table C, etc. (hereinafter “instant patients”), and the Defendant is a medical corporation that opened and operated the “D Hospital.”

B. The Defendant implemented the Non-Formal Influence Signals Act (hereinafter “instant Act”) to the instant patients, and received a total of KRW 54,910,000 from the medical expenses, and the Plaintiff paid the amount equivalent to the above medical expenses to the instant patients as the loss insurance amount.

2. Plaintiff’s assertion and determination of unjust enrichment return

A. The plaintiff's assertion that the defendant implemented the required law of this case corresponding to voluntary non-payment, and received KRW 54,910,000 from the patient of this case. This is null and void in violation of the National Health Insurance Act, which is a mandatory law.

Therefore, the defendant is obligated to return the medical expenses received from the patient of this case to the patient of this case in unjust enrichment. Thus, the plaintiff sought a refund of the insurance money of KRW 54,910,000 on behalf of the patient of this case.

B. The defendant's judgment on the main defense of this case is unlawful, since the plaintiff's claim for return of unjust enrichment does not meet all the existence of the preserved claim and the necessity of subrogation, which is the requirement for the exercise of the right of subrogation of claim.

The obligee can exercise the obligor's right on behalf of the obligor in order to preserve the obligor's claim. The obligee's right of subrogation is closely related to the obligee's right to preserve and the obligor's right to exercise the obligee's right in subrogation, and the obligee's right of subrogation is at risk of not being able to obtain the complete satisfaction of the obligor's claim unless the obligee exercises his/her right in subrogation.