1. The plaintiff's claim is dismissed.

2. Litigation costs shall be borne by the plaintiff.

1. Basic facts

A. On April 13, 2006, the Defendant (mutual name: C) purchased construction machinery listed in the separate sheet (hereinafter “instant construction machinery”) from D on April 13, 2006, as a person engaged in construction machinery rental business, and was determined to pass a regular inspection of the instant construction machinery by March 5, 2013 thereafter.

B. On March 29, 2013, the Plaintiff (E) purchased the instant construction machinery from the Defendant for KRW 163,00,000 from March 29, 2013, and completed the transfer of ownership registration by changing the registration number on April 9, 2013 to F.

C. On March 29, 2014, February 23, 2015, and February 16, 2016, the Plaintiff received the regular inspection of the instant construction machinery, respectively, and received the decision of passing all.

However, in a regular inspection on September 11, 2017, the instant construction machinery was revoked ex officio on January 10, 2018 after the first announcement of October 10, 2017, by the following: (a) the person whose chassis number (G) was inscribed at the time of the registration was indicated to be different from its location and shape; and (b) the original market was publicly notified on October 10, 2017.

On September 11, 2017, the instant construction machinery: (a) the Plaintiff first received the chassis number at the time of the regular inspection on March 29, 2014, and its location and shape are the same as the Plaintiff’s chassis number, its location and shape.

[Ground of recognition] 1 through 5, 9, 10, and 2, each entry of evidence Nos. 1 through 5, 9, 10, and 2, each of the registration of the original and original vehicle of this court, and the inquiry results of the H prosecutor's office, the purport of the whole

2. Judgment on the plaintiff's assertion

A. The Plaintiff’s assertion (i.e., the instant construction machinery was already changed at the time when the Plaintiff purchased it from the Defendant and was subject to ex officio cancellation. Since the Plaintiff was unaware of such circumstances at the time of purchase due to mistake, the instant sales contract should be revoked. The Defendant is obligated to return KRW 163,00,000 from the Plaintiff as unjust enrichment.