A

1. Plaintiff’s ground of appeal

A. As to the first ground of appeal

For reasons indicated in its reasoning, the lower court determined that the Defendant’s payment of KRW 805,00 and KRW 21,299,880 should be deducted from the settlement amount that the Defendant paid to C (hereinafter “C”).

In light of the relevant legal principles and records, the above determination by the court below is just, and contrary to the allegations in the grounds of appeal, there were no errors of misapprehending the relevant legal principles or by misapprehending the bounds of the principle of free evaluation of evidence.

B. In a trial that determines the amount of litigation costs as to the second ground of appeal, where the amount is not determined in a trial that determines the burden of litigation costs, the first instance court rendered a decision to determine the amount of litigation costs at the request of the parties after the judgment becomes final and conclusive or a judgment imposing the burden of litigation costs becomes executory (see Supreme Court Order 2006Ma1488, Mar. 31, 2008). The obligation to reimburse the amount of litigation costs pursuant to the final and conclusive decision of the amount of litigation costs becomes due and the obligor is liable for delay from the time when the obligor becomes aware that the due date has arrived (see Supreme Court Decision 2008Da10051, Jul. 10, 2008).

Based on its stated reasoning, the lower court determined that, on the grounds that C’s judgment was rendered in favor of the Defendant in the lawsuit brought against the Defendant (Seoul Southern District Court 2012Gahap16958, Seoul Southern District Court 2013Na46698, Seoul Southern District Court 2014Gahap109144), the Defendant’s total amount of KRW 27,359,902 (i.e., KRW 10,681,00 + + KRW 10,681,00 + + KRW 5,97,902), the amount should be deducted from the settlement amount that the Defendant would pay to C.

However, in relation to each of the above lawsuits, there is not only lack of evidence to acknowledge that C’s total costs of lawsuit against the Defendant are KRW 27,357,902, but also no evidence to prove that the Defendant received a decision to determine the amount of litigation costs relating to each of the above lawsuits and received such decision, and therefore, the above costs of lawsuit cannot be deducted or offset from the settlement amount to be paid to C by the Defendant.

Nevertheless, the court below, unlike this, deducted the above litigation costs from the settlement of accounts. The court below erred by misapprehending the legal principles as to the deduction of litigation costs or offset, which affected the conclusion of the judgment. The ground of appeal pointing this out is with merit.

2. As to the Defendant’s ground of appeal

A. As to the first ground of appeal, where a creditor subrogation lawsuit filed against a third party obligor on behalf of the debtor is pending in the court while the creditor files a lawsuit with the debtor and the third party debtor who share the subject matter of the lawsuit with the creditor subrogation lawsuit, both lawsuits are the same lawsuit, and thus the subsequent lawsuit is unlawful and brought against the principle of prohibition of double lawsuit. However, in such a case, the criteria for determining the prior lawsuit and the subsequent lawsuit shall follow the prior date of the occurrence of the lawsuit, and if there is an additional change in the lawsuit, the validity of the continuation of the additional lawsuit shall take effect when the document is served on the other party or is delivered on the date of pleading (see, e.g., Supreme Court Decision 91Da41187, May 22, 1992)

According to the records, it can be known that the lawsuit of this case seeking the payment of the settlement amount according to the execution of the transfer security right filed by the Plaintiff against the Defendant by subrogation of C, first becomes effective as the lawsuit filed by C against the Defendant. Thus, this part of the allegation to the effect that the Plaintiff’s subrogation lawsuit of this case constitutes a duplicate lawsuit and is unlawful.

B. As to the second ground of appeal, this part of the ground of appeal is nothing more than the purport of disputing the selection of evidence or fact-finding, which is the exclusive authority of the fact-finding court.

C. As to the third ground of appeal

The provisions on statutory interest rate under the 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, stipulate that "the statutory interest rate under the main sentence of Article 3 (1) of the Act on Special Cases concerning Expedition, etc. of Legal Proceedings shall be 15/100 per annum." Article 2 (1) of the Addenda provides that "it shall be 20% per annum, which was the former statutory interest rate, shall be 15/100 per annum." Article 2 (1) of the Addenda provides that "Notwithstanding the amended provisions of this Decree, the former provisions shall apply to cases in which the first instance trial is in progress at the court as at the time this Decree enters into force, and the statutory interest rate under the former provisions concerning cases for which the first instance trial has not been concluded."

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.

Nevertheless, the part of the court below ordering the payment of damages for delay calculated at the rate of 20% per annum from May 11, 2016 to the date of full payment, which is the day after the date of the decision of the court below, as to the settlement amount as cited by the court below, which affected the conclusion of the judgment by erroneously applying the statutory interest rate of damages for delay. The ground of appeal pointing this out

3. Conclusion

Therefore, the lower judgment is reversed, and the case is remanded to the lower court for further proceedings consistent with this Opinion. It is so decided as per Disposition by the assent of all participating Justices on the bench.

Justices Lee Sang-hoon

Justices Cho Jong-hee

Chief Justice Park Sang-ok