1. The Plaintiff (Counterclaim Defendant) paid KRW 300,282,792 to the Defendant (Counterclaim Plaintiff) and its related amount from January 8, 2016 to September 6, 2018.

1. Basic facts

A. On May 10, 2014, C Co., Ltd. (hereinafter referred to as “C”) subcontracted to the Defendant the construction work for soil and structures (general) among the construction work for the Daegu-gun EF projects that it contracted by D Co., Ltd. (hereinafter “instant construction work”) from D Co., Ltd. during the construction work period of KRW 8,225,913,00 (excluding value-added tax) and the construction period from May 12, 2014 to June 28, 2016.

(hereinafter “instant subcontract”). (b)

On the other hand, before entering into the instant subcontract, C entered into the instant subcontract, separately subcontracted only the construction cost of KRW 265 million to the Defendant among the instant construction works, and around that time, the Defendant agreed to re-subcontract the entire construction cost of the instant construction works that the Defendant would have received from C in the future to the Plaintiff at KRW 7.6 billion (excluding value-added tax).

(hereinafter “instant sub-subcontract.” Meanwhile, the said sub-subcontract contains material costs, and if the Defendant paid the price directly to the material company, it would later settle with 7.6 billion won of the re-subcontract.

From that time, the Plaintiff started the base construction of the underground floor among the instant construction works.

C. On May 10, 2014, C entered into the instant subcontract agreement between the Defendant and C on May 10, 2014, as the Defendant was finally selected as a successful bidder in the said subcontract agreement, and on the same day, C entered into a sub-subcontract between the Plaintiff and the Defendant, setting the construction cost of the instant construction project at KRW 7.6 billion.

Meanwhile, at the time of entering into the instant subcontract, the Defendant and C concluded the instant subcontract with the exception of the part of the basic construction works among the instant construction works in accordance with the terms and conditions of bidding and C’s request, etc.

Since then, on December 26, 2014, the Defendant and C received a separate subcontract from C.