1. The Defendants jointly share KRW 78,071,760 with respect to the Plaintiff and 5% per annum from May 13, 2015 to December 23, 2016.

The facts of recognition are that the Plaintiff is a company engaged in the housing construction business, civil engineering and construction business, etc., and is a contractor of the “D Promotion Project Facility Construction Work” (hereinafter “instant construction”). Defendant C Co., Ltd. (hereinafter “Defendant C”) is a company engaging in the soil construction business, etc., which was subcontracted part of the instant construction work from the Plaintiff. Defendant B is the representative director of Defendant C and the field agent at the construction site of this case.

On May 13, 2008, the Plaintiff and Defendant C’s subcontract concluded with respect to the instant construction project with respect to the installation contract amounting to KRW 3,981,764,00 as to the total construction contract amounting to KRW 3,981,764,00 (the subsequent contract amount is reduced to KRW 3,473,940,00 of the total contract amount of construction works in design modification as set forth in the following sub-paragraph (3) and the deadline for completion is also changed.

[] Around February 2009, Defendant C entered into a subcontract agreement with the Plaintiff to complete construction works among the instant construction works in the amount of KRW 1,007,300,000 (hereinafter “instant subcontract agreement”) up to January 2, 2011, taking into account any change in the design as set forth in paragraph (3) below, the amount of the construction contract was reduced to KRW 967,000,000 (hereinafter “instant subcontract”).

In the first time, during the entire process of the instant construction (an urban planning road with a total length of 1,480 m, width of 15 m) from 1,325.5m to 1,371m to 45.5m in length. However, on April 23, 2009, after considering the risk of safety accidents due to the rapid gradient (7%) of concrete rock-type structures, residents’ civil petitions, construction period, and cost reduction, it was intended to change the structure of concrete rock-type structures into the mar structure.

According to the above design change, the completeer group has patent technology for the manufacture and installation of a sponry structure (hereinafter referred to as "sponson"), and on May 25, 2009.