1. On the second ground for appeal

According to the reasoning of the judgment below, the court below held on April 1, 1993 that the plaintiff (Counterclaim defendant, hereinafter the plaintiff) leased the above store of 12,00,000 won monthly rent of 12,00,000 won to the defendant (Counterclaim plaintiff, hereinafter the defendant) and the defendant operated the dental hospital of this case. The above lease contract was terminated on September 30, 1994 (It is obvious that the court below was erroneous in the facts as of September 30, 1993). Since the fire that was presumed to have occurred within the warehouse near the above store of this case, the defendant could not pay the above rent of this case to the defendant for the reasons that the defendant was unable to perform medical acts for a similar purpose to the above office for rent of this case, and the defendant could not be obliged to pay the above temporary rent of this case to the defendant for the reasons that the defendant could not be obliged to perform medical acts for a similar purpose to the above temporary rent of this case from the office of this case.

However, since the duty of a lessor to use or benefit from an object in a lease agreement and the duty of a lessee to pay rent for rent is in a mutually corresponding relationship, if a lessee is unable to use the object at all due to a lessor’s failure to perform his/her duty to allow him/her to use or benefit from the object, the lessee may refuse to pay the rent in whole within the extent of interference, but if the use or benefit from the object is partly hindered, the lessee may refuse to pay the rent in whole within the extent of interference (see Supreme Court Decision 88Meu1332, 1349, Jun. 13, 1989). Thus, if the Defendant provides dental treatment at the adjoining office where the Plaintiff was granted after fire until August 1994, the lower court did not err by misapprehending the legal principles as to the purpose of the lease in this case and the circumstances leading up to the use of the adjoining office, which affected the conclusion of the judgment. Thus, the lower court did not err by failing to exhaust all necessary deliberations.

2. On the first ground for appeal

According to the reasoning of the judgment below, the court below rejected the plaintiff's assertion that the defendant is liable to pay the amount equivalent to the rent from the termination of the lease contract to the name of the store of this case, on the ground that the defendant did not have any obligation to pay unjust enrichment equivalent to the rent, since it cannot be deemed that the defendant had gained substantial profits by using the store of this case even after the termination of the lease contract

However, according to the records of this case (the plaintiff's brief as of March 23, 1995 and the plaintiff's petition of appeal as of February 21, 1996), it is evident that the plaintiff asserts that the defendant is obligated to pay the amount equivalent to the rent in compensation for damages since the defendant is not obliged to return the store due to the expiration of the lease term, in addition to unjust enrichment determined by the court below, and since the defendant has also recognized the fact that he moved the above dental services to another place by installing a correction device at the store of this case around August 1994, the court below should have judged this point and decided the propriety of the plaintiff's claim. The court below's decision which did not reach this point is erroneous in the misapprehension of the judgment, and since such illegality may affect the conclusion of the judgment, there is a reason to point this out.

3. Therefore, without examining the remaining grounds of appeal, the part against the plaintiff among the judgment below is reversed, and that part of the case is remanded to the court below for a new trial and determination. It is so decided as per Disposition by the assent of all participating Justices.

Justices Kim Jong-sik (Presiding Justice)