The Defendant’s KRW 800,477,600 to the Plaintiffs and its related KRW 6% per annum from April 14, 2017 to January 27, 2021.

1. Basic facts

A. 1) The Defendant, a corporation established pursuant to Article 4 of the Korea Railroad Facilities Corporation Act and engaged in the construction and management of railroad facilities, etc. Of the light wires, the Defendant implemented the “E-F uniformsing project” in which the line 6.8 km between E-F is set up at 51.5 km.

2) In order to support the metal of the above project, the Defendant publicly announced bidding for two construction sections and Nowon-gu Construction Works (hereinafter “instant construction”) among eight construction sections, which serve as the ground for packaging lower parts of the project.

3) On November 7, 2018, Plaintiff A Co., Ltd. (hereinafter “Plaintiff B”) and Plaintiff B Co., Ltd. (hereinafter “Plaintiff B”) commenced rehabilitation procedures, and Co-manager C and D took over the instant litigation procedures around August 21, 2019, but Plaintiff B re-certified the instant litigation procedures on July 14, 2020 after the rehabilitation procedures were completed, and without distinguishing them before and after the takeover.

The Plaintiff Company and G Co., Ltd constituted a joint water supply body with the representative company of the Plaintiff A (hereinafter “joint water supply body of this case”) and participated in the instant construction project tender. The Defendant selected the joint water supply body of this case as a successful bidder.

On the other hand, the equity ratio of the joint water supply company of this case was Plaintiff A 43%, Plaintiff B 15%, and G corporation 42%. On April 27, 2015, G corporation withdrawn from the joint water supply company of this case, and Plaintiff A’s equity shares were changed to 74%, and Plaintiff B’s equity shares were changed to 26%.

B. 1) On December 27, 2006, the joint water supply unit of the instant case determined the construction period from December 27, 2006 to December 28, 2006 as the construction amount of KRW 1,488,330,00, and the total construction amount of KRW 79,734,500,000, and the total construction period of the instant construction from December 27, 2006 to December 26, 201. The joint water supply unit of the instant case entered into and changed the first contract for the instant construction project (hereinafter referred to as the “joint water supply unit of the instant case”) with the Defendant.