A. On May 18, 2015, the Plaintiffs entered into a sales contract with the E and F to purchase the instant real estate at KRW 575 million (hereinafter referred to as “instant sales contract”) by stipulating that the purchase price shall be KRW 575 million (hereinafter referred to as “instant real estate purchase contract”) of the land and the relevant land-building (hereinafter referred to as “the instant real estate,” by combining the land and the housing) outside of Heung-gu G in Gyeonggi-gu, Gyeonggi-gu, and completed the registration of ownership transfer on July 9, 2015.

B. Defendant C and Defendant C’s Intervenor (hereinafter “Supplementary Intervenor”) are licensed real estate agents who arranged the instant sales contract, and Defendant Seoul Guarantee Insurance Co., Ltd. concluded an insurance contract with Defendant C to compensate for property damage suffered by a third party due to the mediation of Defendant C. The Defendant Korea Licensed Real Estate Agent Association is an insurer who entered into a mutual aid agreement with the same content as the supplementary intervenor.

C. At the time of the instant sales contract, the Defendant C and the Intervenor stated that “1% of acquisition tax, 0.2% of special rural development tax, and 0.1% of local education tax” in the “type and tax rate of tax to be paid at the time of acquisition” in the “type and tax rate of tax to be paid at the time of acquisition.”

However, among the instant real estate, housing was subject to heavy taxation as “high-class housing” under Article 13(5)3 of the Local Tax Act and Article 28(4) of the Enforcement Decree of the same Act, and accordingly, the Plaintiffs paid acquisition tax of KRW 65,260,00, special rural development tax of KRW 6,443,00, local education tax of KRW 1,438,000, totaling KRW 73,141,000 (the amount less than 13% of the above sales price) in relation to the acquisition of the instant real estate.

[Ground of recognition] Unsatisfy, Gap evidence 1 to 5 (including additional number), Eul evidence 1 and 2, the purport of the whole pleadings

2. The plaintiffs asserted that (1) Defendant C and the Intervenor are liable for the acquisition of the instant real estate.