1. All appeals by the Defendants against the Plaintiffs are dismissed.

2. The costs of appeal shall be borne by the Defendants.

1. The parties' assertion

A. The Plaintiffs asserted that they concluded a siren contract with the Defendants for each water purifier, but failed to have a water purifier installed, and thus, they cancel the said siren contract.

Therefore, the Defendants should jointly and severally return the rental fee received under the said rental contract to the Plaintiff as unjust enrichment.

B. The Defendants asserted that they concluded a water purifiers agreement with the Plaintiffs (in accordance with the Defendants’ assertion that Defendant D Co., Ltd. entered into a contract under the name of Defendant C, without distinguishing between Defendant D and Defendant C; hereinafter the same shall apply). The agreement constitutes a financial lease agreement in substance, and thus, the Plaintiffs should pay a siren fee regardless of whether to install water purifiers.

Serial 1, Plaintiff A, on September 24, 2016, KRW 15,00, KRW 17,000, Plaintiff A, on September 24, 2016, Plaintiff A, 12, Plaintiff A, on October 24, 2016, KRW 9,610,200, Plaintiff B, on August 23, 2016, KRW 23, Plaintiff B, on August 23, 2016, KRW 14,9,200, KRW 2-3

2. Determination

A. 1) Whether to conclude a siren contract may not be deemed as evidence since there is no evidence to acknowledge the authenticity of each document. Meanwhile, it is recognized that a siren contract (No. 2-2) is authentic, but if it is evident and acceptable that the content of the document is denied, the court recognizes facts different from the content of the document (see Supreme Court Decision 2010Da56616, Nov. 11, 2010), A evidence No. 1, B, and 5, and the entire purport of arguments and arguments in light of the following circumstances, it is insufficient to recognize that a siren contract was concluded with the same content as the content of the contract.

And E are the defendants.