The trademark coexistence consent system, which has been in effect since May 1, 2024, resolves various limitations of indirect methods such as temporary assignment or transfer of trademark rights division when a reason for rejection is notified that a later application trademark is identical or similar to a prior trademark. On the other hand, it is vulnerable to consumer protection and may undermine the role of trademark law as a competition law. The coexistence consent system we have introduced is fundamentally different from major countries such as the United States and Japan examining whether there is confusion of source. Instead of we have focused on strengthening post-control after registration. However, in light of the outline of the trademark coexistence consent system revealed so far, it is still unclear or uncertain, and contains many issues that need to be discussed to determine the direction. The trademark coexistence consent system, which is in the early stages of implementation, still has institutional shortcomings and may face trial and error and various difficulties encountered in practice during the implementation process. In addition, although the trademark coexistence agreement is a private contract under civil law, the act of submitting the consent agreement to the Patent Office is a public act of a private person under administrative law. An understanding of the legal nature of these civil and administrative laws is a prerequisite for establishing an institutional direction. Accordingly, this paper comprehensively reviewed the controversial or insufficient issues in order to properly establish the trademark coexistence agreement system we introduced, taking these various issues into consideration.