The judgment below is reversed, and the case is remanded to the Seoul Northern District Court.

1. As to the grounds of appeal Nos. 1 and 2, the lawsuit is deemed not to have been pending at the appellate court from the beginning (Articles 393(2) and 267(1) of the Civil Procedure Act). However, unlike the withdrawal of a lawsuit to appeal or waiver of the right to appeal, where the final judgment of the first instance exists after the expiration of the appeal period, the first instance judgment becomes final and conclusive retroactively to the expiration of the appeal period (see Supreme Court Decision 2015Meu345, Jan. 14, 2016). According to the reasoning of the lower judgment and the record, the Seoul Northern District Court rendered a judgment on August 13, 2009, stating that “the plaintiffs shall pay 53,212,015 won to each of the plaintiffs and 15% interest calculated at the rate of 5% per annum from the date following the judgment to the date of complete payment (see Supreme Court Decision 207Da1457, Apr. 17, 2017).

Examining these facts in light of the legal principles as seen earlier, the subject case becomes final and conclusive retroactively to the expiration of the appeal period by withdrawing an appeal after the lapse of the appeal period.