1. The plaintiff (Counterclaim defendant)'s main claim is dismissed.

2. The Plaintiff (Counterclaim Defendant) is KRW 25,69,200 to the Defendant (Counterclaim Plaintiff).

A principal lawsuit and a counterclaim shall be deemed to be combined.

1. Basic facts

A. On November 13, 2018, the Plaintiff entered into a contract with the Defendant for manufacturing and supply (hereinafter “instant contract”) by setting the supply price of KRW 55,00,000 with respect to the electronic display boards at KRW 55,00,000. The Defendant manufactured and supplied electronic display boards to the Plaintiff according to the instant contract for manufacturing and supply around January 10, 2019.

B. On November 19, 2018, the Plaintiff concluded a contract with the Defendant on November 29, 2018, under which the construction work ordered by the Naval Education Headquarters (hereinafter “instant electronic sign board”) to contract the Defendant to install an electronic sign board on the said maintenance and improvement work (hereinafter “instant construction contract”), setting the contract period from November 29, 2018 to December 20, 2018, and setting the period from November 29, 2018 to December 20, 2018.

C. On November 30, 2018, the Plaintiff paid KRW 30,000,000 out of the construction price to the Defendant in advance pursuant to the instant construction contract, and the Defendant completed the installation of the instant electronic sign board around December 20, 2018.

On December 28, 2018, the Maritime Education Headquarters requested the Plaintiff to remove and re- install the electronic sign board of this case on the ground that the electronic sign board of this case does not meet the specifications of specifications and that leakage was discovered.

E. Accordingly, the Defendant removed the instant electronic display board on January 15, 2019, and returned the said advance payment to the Plaintiff KRW 30,000,000.

F. Meanwhile, Article 13 of the instant construction contract provides that “Where the execution of the contract has not been completed within the contract period due to a cause attributable to the contractor, the ordering entity shall not only be liable for delay from the original office of the ordering entity, but also be subject to disadvantage such as flat reduction of points and sanctions against unjust enterprisers pursuant to the relevant Acts and subordinate statutes. Accordingly, where the ordering entity suffers damage, the contractor shall pay the penalty equivalent to 80% of the contract amount regardless of the actual amount of damage to the ordering entity.”