The Ministry of Land Infrastructure and Transport declared an event of the faked earthquake-resistance design on November, 2005. The event has become a social issue. The inhabitants of the condominiums, the seller, the builder, the designated confirmation and inspection bodies, and the designated administrative agencies get a difficult problem. This time, the inhabitants of the condominiums are able to make a claim for damages against the seller. However, in actuality, the inhabitants of the condominiums can't receive money, because the seller has no resource. In that case the inhabitants of the condominiums are able to make a claim for damages against the real estate agent. I divide the time when the real estate agent knew the faked earthquake-resistance design, deliberate about the application of the building lots and the buildings transaction business law.