A. Defendant A Co., Ltd. (hereinafter “A”) entered into a contract with the K Co., Ltd. (hereinafter “K”) around January 2014, and received mobile phone terminals from the KK around that time.

B. Around January 2014, Defendant A entered into a guarantee insurance contract for performance (payment) with the insured (hereinafter “instant performance guarantee insurance contract”) on the ground that Defendant A did not perform the liability for damages under an agency contract of a mobile network operator and the obligation for the cost of credit goods on credit (hereinafter “instant performance guarantee insurance contract”) with the Plaintiff, the insured, the insurance amount of KRW 200,000,000, the insurance period from January 1, 2014 to December 31, 2015.

At the time of the conclusion of the above performance guarantee insurance contract, where the Plaintiff was unable to pay the insured amount due to Defendant A’s failure to pay the insurance amount to the insured, Defendant A shall pay the insurance amount without delay, and where delay is made, Defendant A shall pay damages for delay in addition to the interest rate applied by the Plaintiff at the time from the day following the date of payment of the insurance amount to the day of full payment. The overdue interest rate determined by the Plaintiff is 6% per annum from the day following the date of payment of the insurance amount to 30% per annum, 9% per annum

At that time, the defendant A, the representative director of the defendant A, was the wife of the defendant B and B, and as at the time, the defendant A guaranteed the plaintiff's obligation under the performance guarantee insurance contract of this case.

C. It is necessary for Defendant A to increase the amount of insurance coverage in the process of receiving a device from the case. Accordingly, Defendant A changed the content of the instant performance guarantee insurance contract as it increased the amount of insurance coverage to KRW 300 million between the Plaintiff and the Plaintiff on March 25, 2014. Defendant A is a joint guarantor with respect to the Plaintiff’s obligation to be borne by Defendant A according to the modified performance guarantee insurance contract.