1. The defendants' appeal and the plaintiff's incidental appeal are all dismissed.

2. The costs of appeal shall be borne respectively by each party.

1. The reasoning of the court's explanation concerning this case is that the court of the first instance is superior to Article 20 of the 8th sentence of the judgment of the court of first instance (the plaintiff asserts that it is improper to reduce the defendant's liability in calculating the amount of damages by recognizing liability for damages caused by nonperformance of obligation. However, when the debtor is liable for damages caused by nonperformance of obligation to the creditor, the debtor's liability may be limited if there is any negligence on the part of the creditor or if it is necessary to ensure the fairness in bearing the burden of damages. However, it is not permissible in principle to assert that the debtor who intentionally caused the nonperformance of obligation has reduced his liability on the ground of the obligee's negligence. However, it is because it is difficult to limit liability based on the comparative negligence or the principle of fairness if the debtor's final possession of profits caused by the nonperformance of obligation does not result in a result contrary to the principle of fairness or the principle of fairness. Thus, the plaintiff's assertion on the premise mentioned above in the main sentence of Article 20 of the Civil Procedure Act is without merit.

2. As such, the plaintiff's claim of this case is justified within the scope of the above recognition, and the remaining claims are dismissed as it is without merit, and the judgment of the court of first instance is just as it is concluded. Thus, all the defendant's appeal and incidental appeal of the plaintiff are dismissed. It is so decided as per Disposition.