1. Of the judgment of the court of first instance, the part concerning plaintiffs B, D, E, F, and G shall be revoked, and each claim of plaintiffs B, D, E, F, and G shall be filed.

1. The gist of the plaintiffs' assertion is that the defendant is not a licensed real estate agent, but attached a pre-printed paper with the name of the defendant and the telephone number in front of the 11th floor office, "store direct contract of the merchant," "Guarantee of the right to lease of the merchant," "Ice exclusive real estate broker," and "competent H010-(hereinafter omitted)" under the title of "real estate brokerage," thereby violating the Licensed Real Estate Agent Act by carrying out real estate brokerage such as the purchase and sale of the plaintiffs' stores, lease, etc. without the registration of establishment, and received brokerage fees from the plaintiffs. The brokerage commission that the defendant received from the plaintiffs is unjust enrichment and thus should be refunded.

2. Determination:

A. According to the overall purport of each of the statements and arguments filed by Plaintiff A1, 2, 5, 11, and 15 (including branch numbers), the Defendant, as a non-licensed real estate agent, placed an advertisement identical to the description of the cause of the above claim at the I shop located in K in Jung-gu Seoul Metropolitan Government without registering the establishment of a brokerage office, and received KRW 4 million from Plaintiff A by engaging in brokerage in leasing the 2 m of the I building owned by L to Plaintiff A on June 3, 2015, without registering the establishment of a brokerage office.

(A) The establishment registration of a brokerage office constitutes a so-called mandatory law that limits the validity of an agreement on the payment of brokerage fees concluded while operating a real estate brokerage business without registering the establishment of the brokerage office (see Supreme Court Decision 2008Da75119, Dec. 23, 2010). Therefore, an agreement between a non-licensed real estate agent and a plaintiff during the brokerage of a real estate lease agreement without registering the establishment of the brokerage office is in violation of the mandatory provisions.