1. All plaintiffs' lawsuits are dismissed.

2. The costs of lawsuit are assessed against the plaintiffs.

1. Facts of recognition;

A. On May 6, 2013, the Defendant, a contractor for new construction of D apartment, concluded a subcontract with C, setting the construction cost as KRW 1,076,226,30 with respect to the interior d apartment construction as KRW 1,076,226,30.

(hereinafter “instant subcontract”). (b)

C Co., Ltd. entered into a guarantee insurance contract in relation to the execution of the instant subcontract (hereinafter “instant guarantee insurance contract”) with the Seoul Guarantee Insurance Co., Ltd. and issued a guarantee certificate from the Seoul Guarantee Insurance.

C. The Plaintiffs jointly and severally guaranteed the obligation borne by C in relation to the instant guarantee insurance contract.

On the other hand, on October 1, 2016, the Defendant claimed KRW 162,667,240 to the Seoul Guarantee Insurance Contract on the grounds of the nonperformance by C Co., Ltd.

[Ground of recognition] Unsatisfy, Gap evidence Nos. 1 and 2, the purport of the whole pleadings

2. Judgment on the lawfulness of the lawsuit

A. The plaintiffs asserted that since they are joint and several suretys of the guaranteed insurance contract of this case, there is a benefit to seek confirmation of non-existence of joint and several surety obligation or the defendant's non-existence of security deposit claim

B. In a lawsuit for confirmation of confirmation, there must be a benefit of confirmation as a requirement for protection of a right. The benefit of confirmation is recognized only when it is the most effective means to obtain a judgment against the defendant to eliminate such apprehension and danger, and thus, the defendant of the lawsuit for confirmation must dispute the plaintiff's rights or legal relations to cause apprehension and danger in the plaintiff's legal status, and the benefit of confirmation must be against such defendant.

(see, e.g., Supreme Court en banc Decision 96Da11747, Oct. 16, 1997). Therefore, the health care unit for the instant case and the third party against the Defendant.