1. The part of the conjunctive claim in the instant lawsuit is dismissed.

2. The plaintiff's main claim is dismissed.

3...

1. Basic facts

A. The Plaintiff entered into a contract on the consignment of building management (hereinafter “instant consignment contract”) with F, the president of the management body (deficial meeting), with respect to the building E (hereinafter “instant building”).

B. The Plaintiff filed a lawsuit against the Defendants, a sectional owner of the instant building, on November 20, 2018, on the ground that the right to collect management expenses was not granted by the management body of the instant building, following lawful procedures, and the judgment against the Plaintiff was finalized as it is.

[Ground of recognition] Facts without dispute, entries in Gap evidence 2, 4, and 6 (including virtual number), the purport of the whole pleadings

2. Judgment on the main claim

A. Even if the Plaintiff’s assertion does not have legitimate authority to collect the instant management expenses, the Defendants were to have accrued profit due to the Plaintiff’s management affairs, and thus, the Defendants are obligated to return unjust enrichment equivalent to the management expenses to the Plaintiff.

B. In a case where the performance under the contract becomes the benefit of the other party to the contract as well as a third party, if the party who performed the contract can claim for return of unjust enrichment directly against the third party in addition to claiming for the counter-performance under the contract, it would be in violation of the basic principles of contract law by imposing the risk burden under the contract under his/her own responsibility on the third party. In addition, it would result in a violation of the basic principles of contract law. In addition, the contract party, who is the creditor, receives preferential treatment compared to the general creditor of the other party to the contract, thereby impairing the interests of the general creditor, and the third party, who is the beneficiary, infringes on the right of defense, etc. held by the other party to the contract, and thus, in such a case, the party who performed the contract cannot

Supreme Court on November 10, 201