Koshi in learning study – a Hong Kong perspective

Purpose This study aims to explore the roles of Koshi within the Learning Study framework, a Hong Kong adaptation of Lesson Study guided by variation theory. It examines Koshi’s pathways to becoming mentors, facilitators and critical friends, their day-to-day responsibilities and how they refine their practices through educational interventions. Design/methodology/approach A narrative inquiry approach was employed, focusing on two Koshi: a practice-driven Vice Principal (VP) and a research-driven University Lecturer (UL). Data were collected through semi-structured interviews. Cross-case analysis was used to identify common themes and compare their roles, strategies and contributions to teacher learning and professional growth. Findings The study reveals that Koshi play multifaceted roles, including mentors, facilitators and knowledgeable others, bridging theory and practice to support teacher collaboration and reflective inquiry. Leadership support, structured professional development and a culture of knowledge-sharing are critical to their growth. Koshi learn by doing and refining their facilitation techniques through real-world practice and peer feedback. Research limitations/implications The small sample size and Hong Kong-specific focus limit generalisability. Further research across diverse contexts is needed to validate findings. Practical implications Structured training programmes, leadership support and peer collaboration are essential for nurturing Koshi’s capacity to drive teacher professional development. Social implications Koshi foster a culture of reflective practice and collaboration, contributing to sustainable educational improvement and teacher empowerment. Originality/value This study provides new insights into the dual roles of Koshi as both practice-driven and research-driven facilitators in Learning Study. It highlights their impact on fostering professional learning communities and bridging theory with classroom application.