2. All plaintiffs' claims are dismissed.

3. Total costs of litigation are assessed against the Plaintiffs.

2. The parties' assertion

A. The Defendant, from January 1, 2008 to the date of the closing of argument, obtained profits equivalent to the rent of each of the instant lands without any legal grounds by occupying and using each of the instant lands as a road from January 1, 2008, and incurred the same damages to the Plaintiffs, who are the owners of each of the instant lands. Therefore, the Defendant is obligated to return unjust enrichment equivalent to the rent of each of the instant lands owned by the Plaintiffs to the Plaintiffs.

B. From 1936 to 1939, Defendant P divided the instant land into several lots of land in Dongdaemun-gu Seoul, Dongdaemun-gu to construct and sell them as housing sites, and to use them as roads. Accordingly, P renounced the exclusive and exclusive right to use and profit from each of the instant land. Since the Plaintiffs acquired the ownership of each of the instant land while being well aware of the aforementioned circumstances, the Plaintiffs cannot file a claim for return of unjust enrichment on the ground that the Defendant illegally occupied each of the instant land.

3. Determination

(a) Where a land is naturally occurring or is actually used as a road which is classified into a proposed road site and is actually used for public traffic, the owner of the land grants the right to free traffic to neighboring residents or the general public by providing that land as a road, or in interpreting that he/she gives up exclusive and exclusive rights to use and benefit from the land, the circumstance or period he/she owns the land, the details and scale of the sale of the remaining land in installments, the location or nature of the land to be used as the road, and the relationship with other neighboring land;