A. On March 7, 2013, the Plaintiff and the Defendants concluded a contract under which the construction contract amounting to KRW 803,000,000 (including value-added tax) and September 30, 2013 entered into with the Plaintiff for the construction project for site development of a site for an electric source housing complex (hereinafter “instant construction project”) on the ground of the land (hereinafter “instant land”).

B. The Plaintiff and the Defendants determined the special terms of the instant contract as follows: “The estimate shall be referred to as “6..............., shall be completed without any increase or decrease in the quantity,” “in principle, shall make every effort to complete the civil engineering works without any increase or decrease in the quantity,” “7.00 million won shall be borne by the Plaintiff on the basis of the completion date of the construction work” and “8.00 million won shall be completed without any increase or decrease in the contract amount.”

C. The Plaintiff, by January 20, 2014, continued the instant construction work, and on February 12, 2014, filed a claim for construction payment with the Defendants by sending the Defendants a statement of change and a written request for statement of change (two times) with respect to the instant construction work by January 20, 2014.

On February 19, 2014, the Defendants sent to the Plaintiff a certificate of content that “it shall be installed in accordance with the principle of reinforcement soil, to be constructed in a width of 6 meters wide, to be replaced with an excellent road pipe VR, to be constructed in a low level as the first civil engineering, to walking a recycled aggregate, to be constructed with a mixed aggregate, and to be constructed in accordance with the retaining wall construction drawing.”

The amount paid on the payment date (the original recipient) 2013-03-03-08 33,000,000 for Plaintiffs 2014-05-09 30,000,003-28, 2013-03-28,000 for Plaintiffs 2014-06-13, 380, 2013-03-29 187,800,000 for 2013-03-03-29, 2014-06-13, 120, 2000 N 2013-12-031,00,000 for 200,00O204-06-130, 200-130-40, 2000-40, 2030-40-6, 3010-630-6, 2014