1. The judgment of the court of first instance is modified as follows.

All of the plaintiff's claims are dismissed.

2. Applications for the return of provisional payments.

1. Basic facts

A. On April 8, 2015, the Plaintiff, the Defendant, and C Co., Ltd. (hereinafter “C”) concluded a contract for the “Dmiddle School New Construction Project” (hereinafter “instant contract”) with the Daejeon Regional Government Procurement Service and the Chungcheongnam-do Office of Education (hereinafter “ Chungcheongnam-do Office of Education”) as an end-user institution.

At the time of entering into the instant contract, the Plaintiff, the Defendant, and C determined the Plaintiff’s share as 50%, the Defendant’s share as 30%, and the C’s share as 20%, and they jointly implement the joint supply and demand agreement (hereinafter “the first joint supply and demand agreement”) with the content of the joint supply and demand agreement.

B. On June 2015, the Plaintiff and the Defendant entered into a joint supply and demand agreement (hereinafter “the second joint supply and demand agreement”) with respect to the instant contract, and the main contents thereof are as follows.

Article 2 Scope and Effective Period of this Convention shall be limited to the defendant's share during the above construction, and the effective period shall be from the date of the construction contract to the date of expiration of the defect repair liability after completion.

However, this Convention shall remain in force in so far as the rights and obligations relating to this project remain in respect of the ordering entity or a third party.

Article 3 Execution Method

1. The Plaintiff shall lawfully perform the construction project in compliance with the construction specifications, design specifications, specifications, ordering points, and the relevant agency’s instructions, and shall bear full responsibility for the performance of such obligations as contractual construction, manufacture, services, safety, etc. and civil petitions in connection with the construction project.

2. The Plaintiff, as a manager, is responsible for the organization, management, human resources, materials, equipment, etc. of the field.

Article 4 Definitions

1. Performance profit ratio: The ratio of actual profit of the construction of this Convention as analyzed and determined by the plaintiff and the defendant, which is not changed until the day when the effect of this Convention is completed;

2. Profits from execution: Value-added tax, and 2.