1. The plaintiff's claims against the defendants are all dismissed.

2. The costs of lawsuit shall be borne by the Plaintiff.

1. Basic facts

A. On February 22, 2017, the Plaintiff sold to Defendant B the previous 222 square meters (hereinafter “instant real estate”) of the C in official city, Si, for KRW 5 million (hereinafter “instant sales contract”). On February 27, 2017, the Plaintiff completed the registration of ownership transfer with the receipt of No. 5900 on February 27, 2017, Daejeon District Court’s official housing branch.

B. After completing the registration of ownership transfer regarding the instant real estate, Defendant B completed the registration of creation of superficies as the receipt of No. 5902 on February 27, 2017 by the Daejeon District Court No. 5901, the registration of creation of a neighboring maximum debt amount of KRW 32.5 million, and the registration of creation of superficies by the Daejeon District Court No. 5902, Feb. 27, 2017.

C. Meanwhile, at the time of entering into the instant sales contract, the officially assessed value of the instant real estate was KRW 24,397,800, and Defendant B reported the transaction value of the instant real estate as KRW 45 million.

[Ground of recognition] Unsatisfy, Gap evidence Nos. 1, 2, 3, and 4, the purport of the whole pleadings

2. Summary of the plaintiff's assertion

A. The Plaintiff, as a intellectual disabled person, is an incompetent person or incompetent person, and thus, the instant sales contract is null and void.

B. Even if the Plaintiff was not an incompetent person or an incompetent person, Defendant B entered into a sales contract by deceiving the market price, etc. using the intellectual disabled person, and thus, it shall be revoked on the ground of fraud.

Even if it does not constitute fraud, the Plaintiff entered into a sales contract by mistake in the market price and ownership relationship of the instant real estate, and thus, it shall be revoked on the ground of mistake.

C. If the sales contract of this case is invalidated and revoked, the registration of the establishment of a mortgage and the registration of the creation of superficies on the real estate of this case, which was completed by Defendant B to the agricultural cooperative of the U.S. Seosan River.

Therefore, Defendant B should cancel the registration of the above transfer of ownership, the registration of the establishment of the above neighboring land and the registration of the creation of superficies.

3. Determination

(a)the sales contract becomes null and void;