A. On December 19, 2013, Defendant A Co., Ltd. (hereinafter “Defendant A”) and Oral Electric Co., Ltd. (hereinafter “Ofree Electricity”) jointly supplied “C Corporation” (the place of construction: D station, E station transformation station, hereinafter “instant construction”) with the price of KRW 2,710,628,880.

(hereinafter “instant prime contract”). The said payment is based on the premise that the amount equivalent to the value of the high-dong and high-speed iron owned at the construction site of this case should be appropriated for the material cost among the items constituting the construction cost.

B. On January 20, 2014, Defendant A and Oral Power subcontracted the entire construction of the instant construction to the Plaintiff as follows.

(hereinafter “instant subcontract”). In the instant subcontract, like the instant contract for the prime contract, the amount equivalent to the value of the high-dong and high-speed iron owned at the construction site of this case would be allocated to the material cost.

Construction period: Construction cost from January 20, 2014 to February 15, 2015, referring to the part of the contract statement (42 pages, 76 pages) in Gap's entry: 75% of the amount calculated by subtracting the same contract details from the "industrial products, employment, health, pension, long-term care insurance for the aged, retirement mutual-aid installments, pre-use inspection expenses" (hereinafter referred to as "related expenses"), value-added tax separate (tax invoice issuance method): Payment by applying 75% of the contract rate to the progress payment received from Seoul Qat, the ordering place:

C. On November 27, 2014, Defendant B Co., Ltd. (hereinafter “Defendant B”) whose representative is Defendant A’s actual management owner F, drafted a letter of commitment to the payment of construction price as follows in G and the Defendant’s future.

(hereinafter “instant payment contract”). G and the Plaintiff, on October 30, 2014, executing the instant construction project with a maximum of 75 percent (75%) of the amount calculated by subtracting statutory insurance premium for the instant construction project with the payment guarantee letter of contract payment guarantee.