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

2. Costs arising from an appeal and an incidental appeal shall be respectively.

1. The reasoning of the judgment of the court of first instance is as stated in the reasoning of the judgment of the court of first instance. Thus, the court cites this case as it is in accordance with the main sentence of Article 420 of the Civil Procedure Act (it is reasonable to recognize and determine the facts of first instance even when considering the grounds alleged in the judgment of the court of first instance and the evidence additionally submitted by the defendant). 2. Accordingly, the judgment of the court of first instance is legitimate, and both the defendant's appeal and the plaintiff's incidental appeal are dismissed.