1. The Plaintiff (Counterclaim Defendant) paid KRW 37,290,000 to the Defendant (Counterclaim Plaintiff) and against this, from July 11, 2016 to December 27, 2016.

On April 18, 2016, the Plaintiff entered into a contract with the Defendant for the purpose of the supply and installation of polysium at the instant construction site (hereinafter “instant contract”) with respect to the construction of the instant parking building (hereinafter “instant construction”).

According to the instant contract, the construction cost is KRW 124,30,000, and the delivery period is from April 18, 2016 to June 30, 2016, and advance payment (30% of the construction cost) is paid at the end of the following month after the completion of construction work when the contract is issued with advance payment performance guarantee, the intermediate payment (40% of the construction cost) is 50% when the construction is in progress, and the remainder (30% of the construction cost) is paid at the end of the following month after the completion of construction work.

Article 4 of the instant contract provides for the examination of goods and the quality assurance of goods to be supplied as follows:

Article 4 [Inspection of Goods and Quality Guarantee] (1) Materials to be used in the Corporation shall be inspected by the Construction Supervisor before being used, and the materials which have failed to be inspected shall be re-inspectedd immediately.

(2)If Eul (referring to the defendant) fails to promptly transfer any material that it has failed to pass, or is not replaced by a substitute, the Party A (referring to the plaintiff) may remove any material that has been unilaterally rejected or substitute it with a substitute, and the cost shall be borne by Eul.

(3) If, after using materials at the site, the result of a variety of tests is judged to be disqualified, B shall bear all the costs required for reconstruction.

(4) Eul may be used in response to various tests under the quality control regulations, and at the expense of Eul in the event of transformation, consumption, or deterioration for testing all costs and inspections required.

(5) If a person is dissatisfied with the results of the inspection under subparagraph (1), he may request a re-inspection.

In such cases, A shall conduct a reinspection without delay.

On July 10, 2016, the Defendant completed the supply and installation work of polychlorates according to the instant contract.

However, the plaintiff on 2016.