A. The plaintiff is a company aimed at advertising agency business, etc., and C is an individual business operator who conducts advertising agency business under the trade name of D, and the defendant is an advertiser who has entered into an advertising agency contract with the plaintiff and C.

B. On July 1, 2018, the Defendant entered into an advertising agency contract between the Plaintiff and C on July 1, 2018, and between the Plaintiff and C, “C produces advertising materials, and the Plaintiff executes the advertisement produced through TV, etc., and if the Plaintiff claims advertising expenses (media and agency fees) to the Defendant on the last day of the month when the advertisement was executed, the Defendant shall enter into an advertising agency contract with the content that “the advertising agency contract of this case shall pay the advertising expenses to the Plaintiff either in cash or in bills within three months from the 60th of the following month” (hereinafter “instant advertising agency contract”).

(2) After using KRW 529,108,00 as the media cost on August 31, 2018 under the above advertising agency contract, the Plaintiff claimed KRW 582,018,80 as the advertising cost to the Defendant on August 31, 2018 (i.e., media cost of KRW 529,108,000 as the agency fee of KRW 70,759,590).

C. On August 28, 2018, E Co., Ltd. (hereinafter “E”) (hereinafter “E”)

B) On August 28, 2018, the Plaintiff, C, and C: “C manufactures advertising materials; the Plaintiff executes the advertisement produced through TV or other media; and when the Plaintiff claims advertising expenses (media and agency fees) to E on the last day of the month when the advertisement was executed, E entered into an advertising agency contract with the content that “The Plaintiff shall pay the advertising expenses to the Plaintiff in cash or in bills within three months following the following month; and the Defendant shall jointly and severally guarantee all obligations owed by E under the said advertising agency contract (hereinafter “instant joint and several guarantee contract”).

(2) The Plaintiff used KRW 219,106,625 as the media cost on September 30, 2018 under the said advertising agency contract, and thereafter claimed KRW 241,017,288 as the advertising cost on September 30, 2018 (hereinafter “media cost of KRW 219,106,625 as the agency fee of KRW 29,192,505), and used KRW 174,645,705 as the media cost on October 31, 2018, and used KRW 192,110,275 as the advertising cost of KRW 219,106,625 as the media cost of KRW 219,625.