1. Revocation of a judgment of the first instance;

2. The plaintiff's claim against the main defendant A is dismissed.

3. Preliminary Defendant.

1. The reasoning for the court’s explanation on this part of the basic facts is as stated in Article 420 of the Civil Procedure Act, since the reasoning for the judgment of the court of first instance is the same as stated in Article 420 (1) of the same Act.

2. Determination as to the claim against the primary defendant

A. 1) Whether a transfer of funds is unjust enrichment is a means of safe and prompt movement of funds at low cost between banks and bank stores. It is a system under which a bank acting as an intermediary for the smooth handling of large amount of funds flows takes place without involvement in the existence of legal relations, which are the cause of the transfer of funds, and the contents thereof. Therefore, in a case where the remitter enters into a deposit account of the payee pursuant to the basic terms and conditions of deposit transaction and the deposit is recorded in the ledger of the deposit, barring any special circumstance, the deposit contract equivalent to the above deposit amount between the remitter and the receiving bank is established between the remitter and the receiving bank, regardless of whether there is a legal relationship, which is the cause of the transfer of funds between the remitter and the receiving bank (see, e.g., Supreme Court Decisions 2007Da51239, Nov. 29, 2007; 2007Da608127, May 27, 2010).

B. First, we examine whether Defendant A is a bona fide beneficiary.