A. The plaintiff is a company established for the purpose of electrical construction business, etc., and the defendant is a company established for the purpose of communications business.

B. 1) On April 20, 2017, the Plaintiff entered into a sub-subcontract with the Plaintiff and the Defendant (hereinafter “C”)

(C) as between C and D University (hereinafter referred to as “D”)

2) Of the “D Unit E Remodelling project” contracted by the Corporation, the Telecommunications and Electricity and Fire Fighting Corporation (hereinafter “instant prime contractor”).

(1) A subcontract to be subcontracted for construction costs of KRW 1,397,00,000 (including value-added tax) and for construction period from April 20, 2017 to August 23, 2017 (hereinafter “instant subcontract”).

(2) On May 29, 2017, the Plaintiff entered into a sub-subcontract between the Defendant and the Defendant (hereinafter referred to as the “sub-subcontract”) with the cost of construction 653,400,000 (including value-added tax) and the period of construction from April 20, 2017 to August 23, 2017 to which each Defendant re-subcontracted (hereinafter referred to as the “sub-subcontract”) among the contents of the instant sub-subcontract subcontracted by C, and the parts related to the instant case are as follows.

Standard subcontract form (mark) of construction business type;

1. Project owner: D subcontracted project owner;

2. The name of subcontracted project: Types of business registered for subcontracting project for D-E; Communications Corporation.

3. Construction site: The inside and outside of the current science museum in the D unit located in Seongbuk-gu Seoul Metropolitan Government.

4. Period of construction: Value-added tax of 653,400,000 won (including value-added tax) for the supply price of 653,400,000 won (including value-added tax): 594,000,000 won (labor cost: 170,496,216 won): 59,400,000 won.

6. Payment of the price;

(a) An advance payment of KRW 120,000,000 (excluding value-added tax);

(b) Article 49 (Liability for Damages) (1) of the Standard Form Subcontract for Construction Business (U.S.) on the terms of payment of the ordered price, in case the plaintiff or defendant has inflicted damage on the other party in violation of this contract, shall be liable for the damages.