On this basis, the Defendant Company concluded a lease agreement on the instant plant with the owner of the instant plant from April 8, 2017 to November 8, 2018, and paid 3,600,000 won monthly rent for 19 months from November 8, 2018. Since the instant machinery accounts for 40% of the factory area of the instant plant, the Defendant Company has a right to claim restitution of unjust enrichment amounting to 27,360,000 won (i.e., KRW 3,60,000 x 0.0 x 0.4 x 19 months) or a right to claim restitution of unjust enrichment amounting to 24,869,565 won at the time of removal and delivery of the instant machinery (i.e., 14,000,000 business losses amounting to 10,565 won, which is part of the connecting costs after the removal and delivery of the instant machinery, and thus, it is possible to refuse the Plaintiff’s defense.

A person, who possesses another person's articles or securities, has the right to retain such articles or securities until repayment is made, in case where there is a claim created with respect to such articles or securities (Article 320 (1) of the Civil Act). The secured claim of the right of retention shall come due and payable as "claim created with respect to such articles or securities."

In light of the above legal principles, the Defendant Company only paid rent to a lessor upon the lease of the instant factory. As such, the Defendant Company can seek a return of unjust enrichment against a part of the claim against the Plaintiff or claim for damages due to a tort.