[2] In a case where a lawsuit concerning a new claim was filed at an appellate court on September 25, 2015, the “Rules on the statutory interest rate under the main sentence of Article 3(1) of the Act on Special Cases Concerning Expedition, etc. of Legal Proceedings” amended on October 1, 2015 was pending in the court before the enforcement of the amended provisions, but the pleading is terminated after the enforcement of the amended provisions, the time when the statutory interest rate under the amended provisions applies (=from October 1, 2015).

[3] Where an appellate court added a conjunctive claim to the judgment of the court of first instance against the plaintiff after the plaintiff appealeds against the plaintiff, whether the appellate court should determine the conjunctive claim as the first instance court in case where the appellate court did not judge the conjunctive claim while rejecting the main claim (affirmative), and whether the part of the conjunctive claim for which the judgment was omitted is transferred to the appellate court in case where the appellate court did not judge the conjunctive claim while rejecting the main claim (affirmative)

[2] Article 3(1) main sentence of Article 3(1) of the Act on Special Cases Concerning Expedition, etc. of Legal Proceedings, which was amended by Presidential Decree No. 26553 on September 25, 2015 and enforced from October 1, 2015, “the statutory interest rate under the main sentence of Article 3(1) of the Act on Special Cases Concerning Expedition, etc. of Legal Proceedings” (hereinafter “amended Provisions”) amended 20% per annum, which was the former statutory interest rate, to 15% per annum. Article 2(1) of the Addenda of this Decree provides, “Notwithstanding the amended provisions of this Decree, the former provisions shall apply to cases where the first instance trial is pending in court at the time this Decree enters into force, and the legal interest rate for cases for which the first instance trial has not been concluded,” and Article 2(2) of the Addenda provides, “from September 30, 2015, the amended interest rate under the former provisions shall apply to the legal interest rate from September 30, 2015.”

In light of the purport of the amendment of the foregoing provision, when the plaintiff added a new claim at the appellate trial stage, and the lawsuit on the added claim continued before the enforcement of the above amendment provision, but the pleadings have been concluded after the enforcement of the above amendment provision, the interest rate under the previous provision is set at the interest rate until September 30, 2015, and from October 1, 2015, the interest rate under the amended provision is set at the interest rate pursuant to Article 2(2) of the Addenda.

[3] If an appellate court added a conjunctive claim to the judgment of the first instance against the plaintiff after the plaintiff appealed and then the appellate court rendered that an appeal against the previous main claim is groundless, the appellate court shall determine the conjunctive claim as the first instance court. On the other hand, in the case of the preliminary consolidation, several claims are indivisible in one litigation procedure, and thus, if an appeal against the judgment is not determined as to the main claim while rejecting the main claim, the conjunctive claim whose judgment is omitted shall also be transferred to the appellate court, and it shall not be deemed that the part falls under the omission of the judgment and shall not be deemed as continuing

2. The plaintiff's appeal is dismissed.

3. Upon the conjunctive claim added at the lower court, the Defendant shall pay to the Plaintiff 45,00,000 won with the interest of 5% per annum from June 30, 2015 to August 25, 2016, and 15% per annum from the next day to the date of full payment.

4. The plaintiff's remaining conjunctive claims are dismissed.

5. Of the total litigation costs, 80% is borne by the Plaintiff, and 20% is borne by the Defendant, respectively.

A. As to the assertion of misapprehension of legal principles as to the interpretation of expression of intent

Based on the circumstances indicated in its holding, the lower court determined that there was an agreement between the Plaintiff and the Defendant to extinguish at least all the Plaintiff’s obligations pursuant to the final judgment of the second instance lawsuit at the time of concluding the contract. In light of the records, the lower court’s aforementioned determination is justifiable, and it did not err by misapprehending the legal doctrine on the interpretation of expression of intent.

B. As to the assertion of misapprehension of legal principles as to the initial date of damages for delay

Since the obligation to return unjust enrichment is a debt for which the deadline for performance has not been fixed, the obligor is liable for delay only when he receives a request for performance (see Article 387(2) of the Civil Act)

The lower court determined that the Defendant was liable to pay the Plaintiff the amount of KRW 45,00,000 and delay damages, which the Plaintiff transferred to the Defendant as unjust enrichment on the ground that it cannot be deemed that the third party sales contract was concluded between the Plaintiff and the Defendant. Furthermore, the lower court determined that the Plaintiff was liable to pay damages for delay from November 29, 2013 sought by the Plaintiff with respect to the foregoing unjust enrichment.

However, according to the records, the Plaintiff’s statement of grounds for appeal stating the purport of claiming the return of the above KRW 45,00,000 on the ground that it constitutes unjust enrichment can be known that the duplicate of the Plaintiff’s statement of grounds for appeal was served on June 29, 2015 to the Defendant, and there is no other ground to acknowledge that the Plaintiff filed a claim for the return on the ground of unjust enrichment before that date. Therefore, in light of the legal principles as seen earlier, the Defendant is liable for delay after June 29, 2015, when the Plaintiff received a claim for the payment of KRW 45,000,000, which is the time when the claim for the payment was made. Thus, the initial date of calculating damages for delay should be June 30, 2015. Nevertheless, the order to order the Plaintiff to pay damages for delay from November 29, 2013, which the lower court sought, is erroneous in the misapprehension of legal principles

C. As to the assertion of misapprehension of legal principles as to damages for delay under the Act on Special Cases concerning Expedition, etc. of Legal Proceedings

Article 3(1) main sentence of Article 3(1) of the Act on Special Cases Concerning Expedition, etc. of Legal Proceedings, which was amended by Presidential Decree No. 26553 on September 25, 2015 and enforced on October 1, 2015, the statutory interest rate of Article 3(1) main sentence of the Act on Special Cases Concerning Expedition, etc. of Legal Proceedings, is 15/100 per annum (hereinafter “instant amended provisions”). Article 2(1) of the Addenda provides that “The former statutory interest rate of 20% per annum shall be 15/100 per annum,” and Article 2(2) of the Addenda provides that “Notwithstanding the amended provisions of this Decree, the former provisions shall apply to cases pending in the court at the time this Decree enters into force and the pleadings of the first instance have not been concluded” and Article 3(2) provides that “The statutory interest rate of the case with respect to which the first instance trial is pending in the court at the time this Decree, shall be from September 30, 2015.”

In light of the purport of the amendment of the foregoing provision, if the plaintiff added a new claim at the appellate trial stage as in this case, and the lawsuit on the added claim was pending in the court before the enforcement of the above amendment provision, but the pleading is terminated after the enforcement of the above amendment provision, the interest rate under the previous provision is set at the interest rate until September 30, 2015, and it is based on the interest rate under the amended provision from October 1, 2015.

Therefore, the facts that the Plaintiff added the claim for return on the ground that the said KRW 45,00,000 at the appellate stage constituted unjust enrichment are as seen earlier, and the lawsuit on the said claim is clear that the pleadings were concluded on August 25, 2016 after October 1, 2015. As such, the lower court should have applied the amended provisions to order the payment of damages for delay pursuant to the interest rate prescribed by the Act on Special Cases Concerning the Promotion, etc. of Legal Proceedings, etc. for the period after October 1, 2015 on the cited amount, in order to order the payment of damages for delay pursuant to the interest rate prescribed by the amended provisions.

Nevertheless, the lower court’s order to pay damages for delay calculated at the rate of 20% per annum from August 26, 2016 to the date of full payment, which is the day after the date of the lower judgment’s determination, with regard to unjust enrichment cited by the lower court, is erroneous by applying the statutory interest rate for damages for delay. The ground of appeal pointing this out is with merit.

2. Ex officio determination

If the appellate court added the conjunctive claim to the judgment of the court of first instance against the plaintiff after the plaintiff appealed and then the appellate court judged that there is no reason to file an appeal against the previous main claim, the appellate court shall make a determination as to the conjunctive claim in the first instance court. Meanwhile, in the case of the preliminary consolidation, several claims are indivisible in one litigation procedure, and thus, in the case of the preliminary consolidation, the dismissal of the main claim is not judged as to the conjunctive claim while rejecting the main claim, if an appeal against the judgment is not filed, the part of the conjunctive claim, which was omitted, shall be transferred to the appellate court, and it shall not be deemed that the part falls under the omission of the judgment and is still pending in the lower court (see, e.g.

With respect to the instant case, the fact that the Plaintiff added the conjunctive claim while filing an appeal after the Plaintiff’s claim was dismissed at the first instance court. As seen earlier, where the lower court partly admitted the conjunctive claim, the part against the Plaintiff corresponding to the amount cited in the judgment of the first instance should be revoked and the order to pay the cited amount should not be issued, but should have dismissed the Plaintiff’s appeal and ordered the payment of the cited amount at the new preliminary

Nevertheless, the court below revoked the part of the judgment of the court of first instance 45,000,000 won in interest for delay and ordered the payment of the above amount, and dismissed the remaining appeal by the plaintiff. The court below erred by misapprehending the legal principles as to the preliminary consolidation of claims, which led to the failure of the judgment on the preliminary claim, and affected the conclusion of the judgment.

3. Conclusion

Therefore, the judgment of the court below shall be reversed in its entirety, and this case is sufficient for this court to directly render a judgment, and therefore, it shall be reversed as follows in accordance with Article 437 of the Civil Procedure Act.

The judgment of the court below shall be reversed, and the plaintiff's primary claim shall be dismissed as it is without merit, and the judgment of the court of first instance shall be just, and the plaintiff's appeal shall be dismissed as it is without merit. Upon the conjunctive claim added at the court of first instance, the defendant shall pay to the plaintiff the amount of 45,00,000 won which the plaintiff transferred to the defendant as unjust enrichment with the contract deposit, and upon the plaintiff's conjunctive claim added at the court of first instance, a dispute over the existence or scope of the payment obligation from June 30, 2015 to August 25, 2016, which is the date of the judgment of the court below, concerning the existence of the payment obligation of the plaintiff's appeal, and 5% per annum as stipulated in the Civil Act and 15% per annum as stipulated in the Act on Special Cases concerning the Promotion, etc. of Legal Proceedings from the next day to the date of full payment. Thus, the plaintiff's conjunctive claim of this case shall be accepted within the above recognized scope, and the remaining claim shall be dismissed as per Disposition with the assent of all participating Justices.

Justices Kim Shin (Presiding Justice)