1. The defendant's appeal is dismissed.

2. Of the appeal costs, the part arising between the Plaintiff and the Defendant is the Defendant.

1. In full view of the judgment as to the cause of the claim, Gap evidence Nos. 1, 2-1, and 2-2, and the purport of part of testimony and the whole pleadings by witnesses E of the first instance trial, the plaintiff loaned KRW 100 million to the defendant joining the defendant on September 25, 2015 by designating 4% of interest per month, the due date for payment on January 20, 2016, and the defendant did not pay the above loan by the due date. However, the defendant was unable to pay the above loan by the due date upon the defendant's request by the defendant to the defendant, and the defendant jointly and severally guaranteed the above loan debt of the defendant to the plaintiff on February 24, 2016, but the due date has been postponed by June 30, 2016 (the loan certificate of joint and several sureties agreement is No. 2-1, but the above loan certificate is acknowledged (hereinafter referred to as "the above loan certificate").

Therefore, the defendant, as a joint and several surety, is obliged to pay the above loan amount of KRW 100 million to the plaintiff, unless there are special circumstances.

2. Determination as to the assertion by the Defendant and the Intervenor joining the Defendant

A. The Defendant’s joint and several sureties agreement was not established or null and void due to the non-performance of the terms and conditions) that the Defendant and the Intervenor’s Intervenor’s assertion that the Defendant did not pay KRW 100 million to the Plaintiff by January 20, 2016, and E paid the said loan in lieu of the Plaintiff, and E demanded the Defendant’s Intervenor to submit a loan certificate of KRW 130 million in total, including the above KRW 100 million and the previous KRW 30 million lent by E to the Defendant’s Intervenor and the Defendant’s guarantor. On February 23, 2016, the Defendant’s Intervenor requested the Defendant to submit a loan certificate of KRW 130 million,000,000,000 to E upon request of the Defendant, and signed a loan certificate of KRW 130,000,000,000,000 to the Defendant and the Defendant’s guarantor.

However, on February 24, 2016, E, on the following day, deemed that the above loan did not exist, and requested again to prepare the loan certificate in the name of the Plaintiff. Accordingly, the Defendant and the Intervenor joining the Defendant, as well as the Defendant, are KRW 100 million and the borrower.