A. On August 23, 2010, the Defendants contracted a construction work B (hereinafter “instant construction”) with the Korea Rail Network Authority, and subcontracted the construction work of installing household facilities from first to fifth parts around the ground excavated in order to prevent the collapse of the surrounding ground in the course of excavating the ground during the instant construction work (hereinafter “instant construction work”).

B. After completing the construction of a single unit of facilities, the construction was suspended, and the Defendants entered into a subcontract with the Plaintiff on April 14, 2014 regarding the instant earth mounds construction by setting the construction amount of KRW 407,220,000, and the construction period from April 14, 2014 to April 30, 201, and thereafter, the construction period was delayed.

9. A modified contract was concluded to extend to 30.30.

C. On May 2014, the Korea Rail Network Authority demanded the Defendants to modify the design by building a five unit facility and strengthening the four unit facilities. While the Plaintiff installed a four unit facility according to the modified design drawings, the Defendants ordered the Plaintiff to suspend the installation of a four unit of household facilities and dismantle the one unit of household facilities installed by two parts of household facilities. On September 5, 2014, the Plaintiff completed the construction in accordance with the Defendants’ instructions.

The details of the funds paid by the Defendants to the Plaintiff are as follows.

On April 30, 2014, 45,45, 545, 455, 500,000 on April 30, 2014; 45,454, 545, 545, 455, 500,00 on June 30, 3014; 3181, 818, 318, 318, 18242, 42, 300, 300, 309, 30, 1818, 818, 818, 182, 930, 193, 197, 1818, 818, 182, 4242, 00, 300, 305, 309, 196, 305, 309, 309, 2004

E. Meanwhile, the representative director C of Defendant A Co., Ltd (hereinafter “Defendant A”) on October 2014.