A. The Plaintiff’s assertion 1) On February 22, 2016, the Plaintiff is a fire-fighting system installation contract with the Defendant and the Nam-gu Incheon Metropolitan City pertaining to the construction for the extension of ground factories (hereinafter “instant construction”).

(2) The Plaintiff did not pay KRW 50,00,000 for the construction cost despite the completion of the instant construction work in line with the scheduled date of completion. As such, the Defendant did not pay KRW 50,00,000 for the construction cost, the same judgment as stated in the purport of the claim is sought.

B. The defendant's assertion that the construction contract of this case between the plaintiff and the defendant is null and void as a contract concluded by a false conspiracy mark, or the defendant paid most of the construction price of this case to the plaintiff through the non-party

2. The facts acknowledged in accordance with the evidence Nos. 1, 2, and 3 and evidence Nos. 5 of the judgment, namely, the construction contract of this case between the Defendant and the Plaintiff, based on which the Defendant and the Plaintiff were prepared, and accordingly, the Plaintiff was subject to an inspection of completion of fire-fighting systems by designating the Plaintiff as the instant construction business operator, Nonparty B as the supervising business operator, or supervision agency, and the testimony by the witness C, can be acknowledged that the Plaintiff entered into the construction contract of this case with the Defendant and the Plaintiff completed the construction work of this case.

Therefore, the Defendant is obligated to pay the Plaintiff 50,000,000 won with 15% interest per annum under the Act on Special Cases concerning the Promotion, etc. of Legal Proceedings from July 20, 2016 to the day of full payment, which is the day following the delivery of a copy of the instant complaint.

On the other hand, the defendant's arguments cannot be accepted, since there is no evidence to acknowledge that the contract of this case was concluded by a false declaration of intent or that the defendant paid the construction cost of this case.

3. It is so decided as per Disposition by the assent of all participating Justices on the ground that the plaintiff's claim is justified.