A. The content of the instant construction project that the Defendant was awarded a contract by Changwon-si (hereinafter “instant construction project”) is the Defendant’s “B” construction project from Changwon-si around February 21, 2014 (hereinafter “instant construction project”).

(2) The instant construction project was awarded a contract for the total construction cost of KRW 462,069,040 (including value-added tax). The instant construction project is largely divided into the construction project by building and the construction project by business place. The construction project by building is the construction project, in the whole or part of the building, to install a sculpture in the shape of ice gymp, fireworks tree, and to clean the outer wall of the building or to install a new painting. The construction project by business place is to remove existing signboards by business place located in the building and to manufacture and install

B. Contract 1 between the Plaintiff and the Defendant on May 31, 2014, the Defendant entered into a contract with the Plaintiff on the installation of protruding signboards (limited to protruding signboards produced by the Defendant on the wall of the building) in the entire construction of each building in the instant construction project, as well as on the installation of protruding signboards (excluding value-added tax) in the construction of each business place, which are part of KRW 5,000,000 (excluding value-added tax) (hereinafter “instant subcontract contract”).

(2) The instant subcontract contract set the construction period as of June 30, 2014. As to the payment of the price, KRW 30,000,000 out of the construction price by building was paid in advance, and KRW 5,000,000,000, and KRW 5,000,000,000, out of the total construction price by building, were paid in cash within three days after receiving the price from the ordering place.

3) In the instant subcontract agreement, the Plaintiff and the Defendant agreed to “the amount equivalent to 80% of the increases or decreases due to quantity changes” among the construction works for each building, by applying the bid price ratio of the specifications for design. C. Design change at Changwon and the Plaintiff’s additional construction implementation 1) The Changwon price extended the construction period on or before June 2014, and the Defendant expanded the content of the instant construction in quantity or complements the quality thereof to the Defendant.