1. Claim for the warranty bond of the plaintiff (Counterclaim defendant) whose exchange has been changed in the trial at the trial, and the case has been raised at the trial.

1. Basic facts

A. On April 7, 2010, the Plaintiff that forms a joint contractor and the Korea Housing Section Construction Co., Ltd. (hereinafter referred to as “the Plaintiff, etc.”) concluded a contract with a water supply and sewerage construction business office (hereinafter “the main contractor”) for the primary construction of the sewage culvert in the high-sea area, among the works for the maintenance of the sewage culvert in the high-sea area, on the part of the construction of the sewage culvert in the high-sea area.

After that, the plaintiff et al. concluded a contract with the ordering authority on June 20, 201, and on April 25, 201, on April 201, 201, and completed all the construction by the number of teas.

B. Around October 25, 2012, the Plaintiff jointly referred to two companies as Defendant Loading and Jinsung Construction (hereinafter referred to as “Defendant Company”) with the construction cost of KRW 941,102,010 (hereinafter referred to as “instant construction”) and the construction cost of KRW 1,724,631,260 (hereinafter referred to as “Defendant Jinsung Construction”) from October 25, 201 to March 17, 2013 (from October 14, 2012 to April 14, 2013, the construction cost of the instant construction work was extended to 941,102,00 won (hereinafter referred to as “the instant construction work”). From October 25, 2012 to March 17, 2012 to December 14, 2013 (hereinafter referred to as “the instant construction work”).

C. On March 14, 2013, the Plaintiff, etc. was regularly awarded a contract for the construction work of KRW 2,274,470,00 for the fourth portion of the construction work from the ordering authority ( KRW 1,808,510,00 on May 27, 2013; KRW 1,792,329,00 on August 21, 2013); and the construction period from March 18, 2013 to July 10, 2013 (Extension until November 2, 2013).

(However, on May 31, 2013, the ordering party demanded that the Plaintiff complete the 4th portion of the construction work until May 31, 2013. On January 31, 2013, 2013, the payment for the payment for the 61,079,00 won paid on the part of the Defendant Jinsung Construction (on the part of the construction work up to December 2012), Plaintiff 61,453,966 won on March 29, 2013, the advance payment for the 43,230,000 won for Defendant Jinsung Construction (on the part of construction work up to the part of December 2012).