This study deals with case law that has an important impact on the field of civil law. In the area of civil law, many issues straddle the substantive and procedural law portions of the law. The main case law covered in this study concerns dividend and unjust enrichment litigation in civil enforcement proceedings. This issue is an appropriate subject matter when discussing the relationship between substantive law and procedural law because certain interpretive standards have been set by precedent. The study of this case is the starting point for a comprehensive study of the harmonization of substantive and procedural law. In this study, I summarized the academic theories concerning such precedents and clarified the significance of the precedents by referring to Japanese precedents and academic theories as well. This precedent reaffirmed its own position and made it clear that, absent a major change in the law in the future, trial practice will allow general creditor to do unjust enrichment litigation without doing objection to a dividend. However, a detailed investigation into the possibility of unjust enrichment litigation certification specifically must be conducted in future studies. It is important to look for interpretative arguments and necessary legal amendments regarding dividend and unjust enrichment litigation from the perspective of harmonizing substantive and procedural law. A simple substantive or procedural law unique arproach may not lead to a reasonable conclusion. A comprehensive study of substantive and procedural law should investigate whether the use of unjust enrichment litigation should allow an opportunity to modify dividend, and how to ensure an effective procedure for dividend.