1. The Defendant (Counterclaim Plaintiff) paid KRW 19,526,00 to the Plaintiff (Counterclaim Defendant) and its related amount from October 13, 2015 to October 20, 2016.

A principal lawsuit and a counterclaim shall be deemed simultaneously.

1. Basic facts

A. On November 20, 2012, the Defendant concluded a contract for a standard construction contract for private construction works with the construction cost of KRW 4,585,00,000 for the construction cost of the urban-type residential housing construction project (hereinafter “instant new housing construction project”) in the Young-dong, Kimhae-si, Kimhae-si (hereinafter “Gyeongcheon-si”) on November 20, 201, for the construction cost of KRW 4,585,00,000 for the commencement of construction, and October 30, 2013 for the completion of construction works.

B. On February 28, 2013, Gyeongcheon Construction concluded a standard subcontract agreement for construction works (hereinafter “the instant primary subcontract agreement”) with the Plaintiff, setting the construction cost of KRW 670,000,000 (non-taxable site) and the construction period from February 28, 2013 to October 30, 2013 (hereinafter “the instant primary subcontract agreement”).

He agreed to settle the amount at the time of increase or decrease in quantity in the primary subcontract contract of this case.

C. On July 30, 2013, the Plaintiff notified the Defendant, who is the ordering person of the instant new housing construction project, of the fact that the progress payment for the instant construction project was not paid due to the failure to pay it properly. D.

On October 31, 2013, Gyeongcheon National Housing Corporation renounced the new construction of the instant housing.

The Defendant concluded a contract for construction work with an advanced comprehensive construction company (hereinafter referred to as “advance comprehensive construction”) on November 20, 2013, under which the construction work of the instant new housing was set as the construction cost of the instant new construction work, on November 25, 2013; and on June 30, 2014, the Defendant gave up the construction work of the instant new housing.

E. On December 4, 2013, the Defendant, an advanced comprehensive construction, and the Plaintiff entered into a subcontract for construction works (hereinafter “instant secondary subcontract”) with the effect that an advanced comprehensive construction project operator entered into a subcontract for the remaining construction works among the instant construction works with the term from December 6, 2013 to March 31, 2014 (hereinafter “instant secondary subcontract”).