A. On November 8, 201, the Plaintiff entered into a construction contract with Defendant B (hereinafter “instant construction contract”) with the content that the Plaintiff would bear the construction cost (hereinafter “instant construction contract”) on the basis that the Plaintiff calculated the blasting volume at KRW 50,000,000 per 1 cubic meter, and the construction cost of KRW 125,000,000 (=500 cubic meters x 2,500 cubic meters x 2,500) by calculating the blasting volume at KRW 50,00,000 per 1 cubic meter. However, even if there is an increase in the construction cost due to the increase in blasting volume, the Plaintiff entered into a construction contract with Defendant B (hereinafter “instant construction contract”).

B. On July 9, 2012, the Plaintiff paid KRW 12,500,000 as the remainder of the construction cost with respect to the instant construction project until July 10, 2012 to Defendant B, and KRW 16,80,000 as the price for the instant additional construction project, respectively, and even after Defendant B received the said money, agreed to conclude the remainder of the instant construction project and its additional construction project (hereinafter “the instant agreement”).

Defendant C and D guaranteed their obligations under the instant agreement on the same day.

[Ground of recognition] The Plaintiff requested the implementation of the remaining construction of this case under the instant agreement on November 15, 2015 to Defendant B, but Defendant B did not perform this.

Therefore, Defendant B, Defendant C, and D, a joint and several surety, are obligated to pay the Plaintiff the amount equivalent to the cost of the remaining construction works of this case as damages for nonperformance of the foregoing obligation, as well as the delayed payment amount of KRW 71,659,500.

Judgment

Under the overall purport of the arguments, based on facts as to the cause of the claim, Gap evidence Nos. 6 (including the number of pages), the appraiser G’s appraisal result, Defendant B bears the duty to perform the remaining construction of this case under the agreement of this case, and Defendant C and D.