1. The Defendant’s KRW 29,746,953 as well as the Plaintiff’s KRW 5% per annum from November 9, 2017 to August 24, 2018, and the following.

1. Basic facts

A. Nonparty Mesofi Co., Ltd. (hereinafter “Mesofi”) awarded a contract for “new construction of a private teaching institute for Mesofiology” to Nonparty 3 Construction Co., Ltd. (hereinafter “Mecsofi Construction”). On July 10, 2015, the Mecsofi Co., Ltd. subcontracted the construction of machinery in the said construction amounting to KRW 1.65 billion to the Defendant.

On October 22, 2015, the Defendant re-subcontracted the Plaintiff with the contract price of KRW 257,400,000 (including value-added tax) and the construction period from October 22, 2015 to November 30, 2015.

(hereinafter “instant subcontract”). According to the instant subcontract, the Defendant had the Plaintiff pay the subcontract price to the Plaintiff within 35 days from the date of receipt of the object.

B. On December 28, 2015, the Plaintiff completed the installation work of a system boiler and subsequently supplied hot water to the said Mesium. However, on the part of the main contractor, the Plaintiff raised some problems in the boiler performance.

On January 20, 2016, the Plaintiff accepted the order due to the malfunction of the system boiler, such as the damage of the presses of the system boiler around January 20, 2016. On March 11, 2016, the Plaintiff confirmed that the system boiler appears to have a good performance on the part of the metricker’s side, conducting a performance test several times from March 11, 2016.

C. On December 24, 2015, the Defendant paid the Plaintiff KRW 20 million as the subcontract price, but did not pay the remainder.

On April 29, 2016, the Defendant issued to the Plaintiff a letter of undertaking to pay KRW 237,400,000,000,000 for unpaid amount, out of the subcontract price of the instant case, to the Plaintiff in installments from May 4, 2016 to June 10, 2016.

Although there was a content that the defendant would not raise any objection against any civil or criminal measure if he/she fails to comply with the above commitment, the defendant did not pay the subcontract price to the plaintiff.