1. All of the plaintiffs' claims are dismissed.

2. The costs of lawsuit are assessed against the plaintiffs.

1. The plaintiffs' assertion

A. In around 2010, Plaintiff A newly constructed a building on the land as indicated in the separate sheet owned by the Defendant (hereinafter, indicated in the separate sheet omitted), and as a part of the wall installed between the land and the three land owned by the Defendant was destroyed, Plaintiff A removed the wall and installed a new wall.

B. Plaintiff B, at around 2015, intends to newly construct a building on two land owned by the Defendant and a part of a wall installed between the two land and the three land owned by the Defendant, which was destroyed by the removal. Despite the installation of the said wall on two land, the Defendant was obstructing the removal of the destroyed wall and new construction by asserting that it was installed on three land owned by the Defendant, even though the said wall was installed on two land.

C. Although the land owned by the plaintiffs 1, 2 and the land owned by the defendant 3 are adjoining one another, the boundary is unclear, and there has been several disputes between the plaintiffs and the defendant, so the plaintiffs may seek confirmation of the land boundary against the defendant.

According to Article 237 of the Civil Code, a person who owns adjoining land may construct a usual fence at common expenses.

As such, the owner of one land may request cooperation from the owner of the adjacent land in establishing a fence, and the owner of the adjacent land has a duty to cooperate with him, and this legal doctrine applies to the case where removal and new installation or repair are required due to the damage of the existing fence. Therefore, the defendant has a duty to permit the installation of a fence, such as the written claim by the plaintiffs.

2. We examine the plaintiffs' assertion. The boundary between each land owned by the plaintiffs and the land owned by the defendant is unclear, or each fence installed between the plaintiffs' land and the land owned by the defendant is installed only on the land owned by the plaintiffs, or the part to be newly installed by the plaintiffs.