According to the records, the Plaintiff filed a claim against Defendant 1 for the delivery of the instant building and the return of unjust enrichment equivalent to the rent. The first instance court dismissed the claim for delivery of a building among them and accepted part of the claim for return of unjust enrichment, and Defendant 1 appealed against the part against which the Plaintiff lost. The lower court accepted the appeal regarding the claim for delivery of a building and accepted the Plaintiff’s claim on that part, but dismissed the Plaintiff’s appeal regarding the claim for return of unjust enrichment, and Defendant 1 appealed to the entire lower judgment.

Therefore, the judgment of the court below on the claim for return of unjust enrichment against Defendant 1 is not a judgment unfavorable to the above defendant, rather than the judgment of the court of first instance against which Defendant 1 did not appeal. Accordingly, Defendant 1 does not have any interest in dispute as to the part of the judgment below. The appeal by Defendant 1 is unlawful and cannot be corrected.

2. Judgment on the ground of appeal by Defendant 1 as to the part on the claim for delivery of a building

A. As to the first ground for appeal

Based on its adopted evidence, the court below determined to the effect that, in light of the following circumstances: (a) the Plaintiff was awarded the instant real estate stated in the attached Form of the judgment below in the auction procedure and completed the registration of ownership transfer in the future; (b) Defendant 1 occupied the building portion stated in the above paragraph (a) of the judgment below; (c) Defendant 1 paid a total of KRW 29,500,000 to Defendant 1, such as roof penting installation works, roof waterproofing construction and roof board construction works, electrical equipment construction, water supply and boiler installation works, and stove construction works, etc.; and (d) this constitutes a beneficial expense that increases the objective value of the instant building; (c) Defendant 1 was the child of Defendant 2 and the Nonparty who owned the instant building was the first owner of the instant building; and (d) the Nonparty and Defendant 1 received a fixed date after the first decision to commence the auction on the instant real estate, the Defendants were the most beneficial lessee; and therefore, Defendant 1 cannot claim reimbursement against the Plaintiff as a legitimate lessee.

In light of the records, the fact-finding and judgment of the court below are just, and contrary to the allegations in the grounds of appeal, there are no errors in violation of logical and empirical rules and free evaluation of evidence

B. Regarding ground of appeal No. 2

Even if examining the record, the court below did not err by infringing on the above defendant's right to trial or defense, as alleged in the grounds of appeal.

C. Regarding ground of appeal No. 3

1) The right to claim reimbursement of beneficial expenses against the person who was restored to the possessor under Article 203(2) of the Civil Act is established when the possessor is not entitled to lawfully possess the property, such as a contractual relationship, and is obligated to comply with the owner’s claim for reimbursement of the expenses. In such cases, the possessor may exercise the right to claim reimbursement of expenses against the owner at the time of recovery of possession, i.e., the person who was the owner at the time of disbursement of the expenses, regardless of who was the owner at the time of disbursement of the expenses. However, in a case where the possessor had legitimate title of possession, such as a contractual relationship, at the time of disbursement of the expenses for beneficial expenses, the provisions of Article 203(2) of the Civil Act governing the contractual relationship apply to the repayment of the expenses for the said expenses. Thus, the possessor may exercise the right to claim reimbursement of expenses against the other party to the contractual relationship, etc., and cannot claim reimbursement of expenses against the owner at the time of recovery of possession, other than the other party to the contractual relationship, etc. (see Supreme Court Decision 2001Da64752, Jul.).

2) According to the records, Defendant 1 asserted that there exists a lien based on the right to claim reimbursement of beneficial costs (record 35 pages) without specifying the legal relations that form the basis for the claim for reimbursement of beneficial costs, or that there exists a lien based on the loan for use (record 389 pages).

Therefore, as seen earlier, the lower court recognized Defendant 1’s disbursement of the beneficial expenses for the instant building. In so doing, the lower court should have deliberated and judged whether Defendant 1 has the right to claim reimbursement of beneficial expenses based on the loan relation, and whether the right of retention based on the right of retention is recognized, in light of the aforementioned legal doctrine.

Nevertheless, the judgment of the court below which did not reach this point is erroneous by omitting judgment on the plaintiff's assertion and affecting the conclusion of the judgment. The ground of appeal on this point is justified.

3. Determination on Defendant 2’s grounds of appeal

A. Although the lower court’s determination as to whether Defendant 2 is a legitimate lessee of the instant building, as otherwise alleged in the grounds of appeal, the person who disbursed the cost of beneficial benefit to the instant building is not Defendant 1 and Defendant 2, and Defendant 2 cannot claim reimbursement of the cost of beneficial benefit, and therefore, there is no room to acknowledge the right of retention.

Ultimately, the court below's rejection of Defendant 2's claim on the lien is just, and there is no error of law as alleged in the ground of appeal.

B. In addition, even if examining records, the court below did not err by infringing on the above defendant's right to trial or defense, as alleged in the grounds of appeal.

4. Conclusion

Therefore, Defendant 1’s appeal as to the portion of the claim for return of unjust enrichment among the judgment below is dismissed. Of the part against Defendant 1, the part concerning the claim for delivery of real estate among the part concerning Defendant 1 is reversed, and that part of the case is remanded to the court below for further proceedings consistent with this Opinion. Defendant 2’s appeal is dismissed, and the costs of appeal against Defendant 2 are assessed against Defendant 2 who is the losing party. It is so decided as per Disposition by the assent

Justices Jo Hee-de (Presiding Justice)