1. All of the counterclaims filed by the Plaintiff (Counterclaim Defendant) against the Defendant (Counterclaim Plaintiff) and the Defendant (Counterclaim Plaintiff).

1. We examine, ex officio, whether the counterclaim of this case is legitimate or not.

A counterclaim, in case where a claim which has become the object of a lawsuit is related to a claim or defense method of the principal lawsuit and the litigation procedures are not remarkably delayed, may be instituted not later than the time the pleadings in the principal

(Article 269(1) of the Civil Procedure Act. However, the instant counterclaim by the Defendant-Counterclaim Plaintiff is unlawful on the ground that it is apparent that it was filed on April 3, 2019, which was after the closing of argument in the principal lawsuit, and it does not meet the requirements under Article 269(1) of the Civil Procedure Act.

2. Determination on the main claim

A. We examine the legitimacy of the claim against the Defendant (Counterclaim Plaintiff) ex officio.

Since a final and conclusive judgment in favor of a party has res judicata effect, if the party who has received the final and conclusive judgment in favor of the party files a lawsuit against the other party in the same lawsuit as the previous suit in favor of the final and conclusive judgment, the subsequent suit is unlawful

However, comprehensively taking account of the overall purport of the statements and arguments by Gap evidence Nos. 1 and 3, the plaintiffs received a favorable judgment on the same claim as the purport of the claim of this case against the defendant-Counterclaim (Counterclaim) in the case of this Court 2015Gahap13028, 2016Gahap13872 (Intervention), and 2017Gahap11422 (Counterclaim) on January 24, 2018, and the judgment became final and conclusive by dismissal of appeal, the plaintiffs' claim of this case against the defendant-Counterclaim (Counterclaim) is unlawful as there is no benefit in protecting rights.

B. Judgment on the claim against the defendant 1) The reasons for the claim are stated in the annexed sheet. 2) Judgment by service by applicable provisions of law (Article 208(3)3 of the Civil Procedure Act)

3. Conclusion, the plaintiffs' claim on the main claim against the defendant (Counterclaim) and the counterclaim by the defendant (Counterclaim Plaintiff) are dismissed in entirety by being unlawful, and the plaintiffs' claim on the main claim against the defendant is accepted with merit, and it is so decided as per Disposition.