However, in the case of breach of trust, the intrinsic content of another person’s business is to have the duty to protect or manage another person’s property based on a fiduciary relationship, and the fiduciary relationship includes a fiduciary relationship in accordance with the good faith principle, not limited to statutes, contracts, or legal acts.

In light of the fact that the defendant, while proceeding with the victim D to the third year of F development and withdrawing from the company, entered into an agreement to jointly carry out the fourth year project with the victim company, etc., the fiduciary relationship between the defendant and the victim company is recognized, and the defendant constitutes "a person who administers another's business" but the court below erred by misapprehending legal principles that affected the conclusion of the judgment.

2. Determination

A. The summary of the instant facts charged is that the Defendant, from March 1, 2005 to August 17, 2012, was in office as the head of the headquarters for the solution project of the victim D Co., Ltd. (hereinafter “victim”) from around March 1, 2005 to around August 17, 2012, and the victim company took overall charge of the F Development as the first, second, and third PM of the “E Development” project ordered by the Korea Transport Institute. On August 20, 2012, the Defendant established and operated G Co., Ltd., the same company as the victim company.

1. The defendant prepared a written oath to the effect that he/she will not return and leak trade secrets and related data at the time of his/her employment and retirement, and the victim company manages bid proposals, etc. as major assets through security organization guidelines, security management regulations, etc., the defendant is prohibited from divulging major assets he/she acquired while in his/her office, and there was a duty to return or delete them at the time of retirement.

Nevertheless, the defendant around August 2012.