1. The defendant's appeal is dismissed.

2. The costs of appeal shall be borne by the Defendant.

3.Paragraph 1. of the text of the judgment of the court of first instance.

1. Facts of recognition;

A. The Plaintiff is a company running ready-mixed manufacturing business.

Upon request from C from February 21, 2018 to May 15, 2018, the Plaintiff supplied ready-mixeds equivalent to KRW 24,565,860 in total at the site of the Da (E Museum)-si Construction Project for Housing and Commercial Building (hereinafter “instant construction project”), and received KRW 10,000,000 from C.

B. On April 12, 2018, the Defendant signed a signature on the joint and several surety column of the ready-mixed order contract that the Plaintiff wishes to supply ready-mixed to the F’s representative C (the contract includes “G” as “G”).

[Ground of recognition] Facts without dispute, Gap 3, 6 evidence, Eul 2, the purport of the whole pleadings

2. According to the above facts of determination as to the cause of the claim, since the Defendant jointly and severally guaranteed the obligation of ready-mixed to the Plaintiff by C, the Defendant has a duty to pay 14,565,860 won (=24,565,860 won - 10,000,000 won) for ready-mixed which the Plaintiff had not been paid as well as 15% per annum under the provisions of the main sentence of Article 3(1) of the former Act on Special Cases Concerning Expedition, etc. of Legal Proceedings, and the statutory interest rate of Article 3(1) of the former Act on Special Cases Concerning Expedition, etc. of Legal Proceedings, from April 17, 2019 to May 31, 2019 (amended by Presidential Decree No. 29768, May 21, 2019) to the Plaintiff at the rate of interest rate of 15% per annum under the main sentence of Article 31(1) of the Act on Special Cases Concerning Expedition, etc. of Legal Proceedings.

3. The defendant's defense, etc. 1) As to this, the defendant signed the order of ready-mixed (the certificate No. 3 is signed in the column of joint and several sureties, but it is not the contract as joint and several sureties, and the above contract merely is not the form of a fixed contract but the original contract, and it is not the joint and several sureties's obligation to pay back to the plaintiff by the defendant.