1. All of the plaintiffs B and C's claims for confirmation of invalidation and the remaining plaintiffs' lawsuits are dismissed.

2. Plaintiffs B, and .

1. Facts of recognition;

A. The plaintiffs are those who have sold or acquired the right to the shopping mall in Yongsan-gu Seoul Metropolitan Government (hereinafter "the shopping mall in this case"), and the defendant is the implementer who newly built and sold the shopping mall in this case, and the E Co., Ltd. (hereinafter "E") is the contractor who newly built the shopping mall in this case.

B. From October 2015, the Plaintiffs entered into a contract to purchase each of the instant commercial buildings from the Defendant (hereinafter “instant sales contract”) and entered into a supply contract (hereinafter “instant supply contract”). The key issues of the instant supply contract are as follows.

Article 1 [Methods for Payment of Amount to be supplied] (1) The plaintiff shall pay the amount to the defendant with the account prescribed in paragraph (3) at the due date for payment as follows:

The payment deadline and the amount to be paid under the instant sales contract are different for each individual sales contract, and the ratio of the amount to be paid is 10% of the contract amount, intermediate payment 30%, and 60% of the balance, and the payment deadline is the same.

10% of the remainder (60%) of the down payment (10%) (30%) of the intermediate payment (60%) (60%) of the second (10%) of the 10%) of the 1st (10%) of the 10%) of the 10th (10%) of the 10th (10%) of the contract.

Accordingly, if the period of designation of the tenant is advanced, the plaintiff shall pay the balance in lump sum during the period of designation of the tenant who is advanced, and in such cases, the advance payment discount shall not apply.

Article 3 (Late Payment and Compensation for Delay) (1) When the period for which an agreement has elapsed due to the delay in the payment of intermediate payments and remainder, the Plaintiff shall pay for the overdue days by applying 8.13-12.13% per annum, which is the sum of the average of the overdue interest rates among the deposit banks announced by the Bank of Korea at the time of the initial supply contract, and the additional interest rate per annum for each overdue period determined by the highest bank at the time of the initial supply contract, to the overdue period, and when the amount of the payment falls short of the