Broadening science inquiry: a longitudinal lesson study on scaffolding Gen-taiken (living experience) in a Japanese microschool

Purpose This study elucidates instructional strategies for introducing inquiry-based science to lower-elementary students (Grades 1–4) in a Japanese microschool. Addressing the conflict between young learners' intuitive theories and scientific explanations, it investigates how teachers design “entry points” bridging daily life with scientific concepts. Design/methodology/approach Adopting a Constructivist Grounded Theory Approach (Charmaz, 2006), I analyzed teacher discourse from a two-year longitudinal Lesson Study (13 meetings, 2023–2025) involving eight teachers, using the scaffolding means of questioning and instructing (van de Pol et al., 2010) as sensitizing concepts. Findings The analysis identified a three-component framework: Entry Points activate prior knowledge and daily-life experiences; Continuous Scaffolding nurtures prediction and causal reasoning; and Broadening Inquiry validates Modeling, Problem Solving and Concept Clarification alongside Comparative Experimentation. From this analysis, the study generates Gen-taiken (現体験, living experience) – learners' intensified, purposefully guided engagement with experience as it unfolds in the present – as the experiential foundation for conceptual change. Research limitations/implications Because the theory was generated within a single microschool with small, mixed-age classes and from teachers' reflective discourse rather than measured student learning, I offer Gen-taiken and the framework as transferable concepts to be tested, not generalizations. Originality/value The study proposes Gen-taiken as a new theoretical concept, distinguished from the established Japanese notion of proto-experience (gen-taiken) and argues that Broadening Inquiry is not a dilution of science but the deliberate design of living experience that lays, here and now, the experiential foundation for rigorous scientific thinking.