A. According to the purport of Gap evidence Nos. 2 and 3 as a whole and arguments, the plaintiff completed construction works by subcontracting the removal of the Incheon Seo-gu and B site (i.e., dismantling of asbestos and dismantling of construction structures) from the defendant, and the plaintiff was paid KRW 8,000,000 among the construction cost of KRW 45,573,000 and was not paid the remainder of the construction cost.

B. Therefore, the Defendant is obligated to pay the Plaintiff the remainder of the construction cost of KRW 37,573,00 and the damages for delay calculated by the rate of KRW 15% per annum from December 5, 2017 to the date of full payment, which is the day following the day when the original copy of the instant payment order was served on the Defendant.

C. As to this, the defendant alleged that he agreed to reduce the construction cost of KRW 5,000,000 due to the lack of part of the construction work, but there is no evidence to acknowledge this, so the defendant's above assertion is without merit.

2. Conclusion, the plaintiff's claim is justified and acceptable.