1. The plaintiff (Counterclaim plaintiff)'s principal lawsuit against the defendant (Counterclaim plaintiff), the defendant's claim against the defendant, and the defendant (Counterclaim plaintiff)'s counterclaim.

1. Basic facts

A. The Plaintiff is the legal management body of A building (hereinafter “instant building”) with the 4th underground floor and 10th above ground located in Yeongdeungpo-gu Seoul Metropolitan Government, and was planned to remodel the front outer wall reduction of the instant building from the hydro-pampin to the Aluminium complex panel (hereinafter “instant construction”). In around 2018, the Plaintiff planned to implement remodeling construction (hereinafter “instant construction”).

B. On October 25, 2018, the Plaintiff concluded a contract for design and supervision of a building with a total service cost of KRW 17,500,000 (excluding value added tax) (hereinafter “instant design contract”) for the instant construction with Defendant C, who operates the “E”, and the scope of the service for the instant construction as “the preparation of shop design drawings, other books necessary for the remodeling of construction water, and construction works,” and the design and supervision of the building with the total service cost of KRW 17,50,000 (excluding value added tax), and the Plaintiff agreed to pay KRW 5,250,000 each at the time of the completion of the permission for large-scale repair, at the time of the commencement of the construction report, and KRW 3,50,000 each at the time of filing an application for approval for the use.

(c)

On December 31, 2018, the Plaintiff obtained permission for substantial repair with respect to the instant construction project from Yeongdeungpo-gu Office.

(d)

On October 31, 2018, the Plaintiff paid KRW 11,550,000 in total to Defendant C by paying KRW 5,250,000 and value added taxes, and KRW 5,250,000 on January 30, 2019.

E. On January 30, 2019, the Plaintiff entered into a construction contract with the Defendant Company with the total construction cost of KRW 220,000,000 (including value added tax) (hereinafter “the instant construction contract”); and on March 8, 2019, paid down payment of KRW 44,000,000 (including value added tax) to the Defendant Company.

F. The supervision service cost of the instant design contract was KRW 6,400,000 ( separate value added tax). Around March 2019, the Plaintiff concluded a construction supervision contract with the Defendant C with a view to KRW 7,000,000 ( separate value added tax) (hereinafter “instant supervision contract”). G. The Defendant Company surrounded the instant building from March 12, 2019 to March 14, 2019.