The appeal is dismissed.

The costs of appeal are assessed against the defendant.

The grounds of appeal are examined.

1. As to the grounds of appeal Nos. 1 and 3, the lower court, on the grounds as indicated in its reasoning, held that, in principle, the Plaintiff is the owner of the instant building. However, the Plaintiff is merely obligated to allow the use of the instant building only in cases where E Co., Ltd. (hereinafter “Nonindicted Company”) directly occupies or uses the instant building or rents it with the Plaintiff’s consent pursuant to Article 9(1) of the Real Estate Security Trust Contract, etc., and the Defendant occupied the instant building without the Plaintiff’s consent, which determined that the Plaintiff suffered considerable loss in the rent, thereby receiving a claim for return of unjust enrichment from

Examining the relevant legal principles and records, the lower court did not err in its judgment by misapprehending the legal doctrine on the requirements for establishing unjust enrichment, etc. as alleged in the grounds of appeal.

In addition, the lower court did not deem that the Defendant occupied the building of this case even during the rehabilitation procedure against the Defendant, as alleged in the grounds of appeal, it did not err by misapprehending the ownership of the rights and obligations relationship or the rehabilitation procedure.

2. As to the ground of appeal No. 2, the lower court determined that the Plaintiff’s claim for return of unjust enrichment did not go against the good faith principle on the ground that the Plaintiff could not be deemed to have known the conclusion of the instant lease agreement between the Defendant and the Nonparty Company or the Defendant’s possession

Examining the relevant legal principles and records, the lower court did not err in its judgment by misapprehending the legal doctrine on the violation of the good faith principle, contrary to what is alleged in

3. Therefore, the appeal is dismissed. It is so decided as per Disposition by the assent of all participating Justices on the bench.