1. It is reasonable to view that the obligation of a local government-invested company to pay the transfer of ownership to a local government-invested vehicle upon the termination of a local government-invested contract and the obligation of a local government-invested company to pay the management expenses in arrears, etc., in light of the principle of equity. Thus, if the local government-invested company continues to operate a local government-invested vehicle with the right of defense of simultaneous performance, while the local government-invested company holds the ownership of the local government-invested vehicle, and has operated the freight truck by using the registered name of the local government-invested company's freight trucking services, barring any special circumstance, the local government-invested company has obtained profits equivalent to the local government-invested fees agreed upon under the local government-invested contract by running the cargo trucking service using the registered name of the local government-invested company's freight trucking services without any legal ground, and the above profits that the local government-invested company received shall be returned to the local government-invested company as unjust enrichment (see Supreme Court Decision 2003Da37136, Nov. 28, 2003).

2. The court below acknowledged the following facts: (a) around April 20, 202, the plaintiff entrusted the title of the instant automobile to the defendant company and paid the rent to the defendant company; and (b) the plaintiff entered into an entrustment management contract to operate and manage the instant automobile on its own account; (c) around April 21, 2006, the plaintiff expressed his intention to terminate the instant automobile to the defendant company; and (d) the plaintiff continued to operate the instant automobile by using the state registered in the name of the defendant company until the closing of argument in the court below until the date of closing argument; (c) barring any special circumstance, the plaintiff shall be deemed to have obtained unjust enrichment equivalent to the land admission fee under the instant land entry contract from the time of termination of the instant land entry contract until the registration of transfer of ownership of the instant automobile is completed; and (d) this obligation to return it to the defendant company; and (e) this obligation shall be deemed to have a concurrent performance relation with the obligation to pay the ownership transfer registration procedure for the instant automobile by the defendant company to the defendant company.

Nevertheless, without examining and determining the existence and scope of the Plaintiff’s obligation to return unjust enrichment or to settle accounts as above, the lower court concluded that there was no overdue payment or fine for negligence at the time when the Plaintiff expressed its intention to terminate the instant land entry contract, and rejected the Defendant Company’s simultaneous performance defense. The lower court erred by misapprehending the legal doctrine on the legal relationship following the termination of the land entry contract, or by failing to exhaust all necessary deliberations, thereby adversely affecting the conclusion of the judgment.

3. Therefore, the lower judgment is reversed, and the case is remanded to the lower court for further proceedings consistent with this Opinion. It is so decided as per Disposition by the assent of all participating Justices on the bench.

Justices Park Si-hwan (Presiding Justice)