This study documents the inclusive, deliberate, and unintended educational practices in Japan for mathematically gifted students. It also aims to identify various schools' strengths and challenges in improving the mathematics education of these students. Case studies with multisite designs were undertaken in five middle schools selected using purposive sampling. Mathematics education practices -- assessed in terms of assessment, mathematics instruction, support and interventions, and teachers' collaboration -- guided the data collection and analysis. The primary goal of this study was to describe current school practices and identify common strengths and challenges (including outlier practices across schools) which were valuable in generating conclusion regarding how certain practices might lead to different student and/or teacher outcomes.