Abstract
<p>Global challenges such as climate change and food insecurity are closely linked to the unsustainable structures of dominant food systems. These systems are reinforced by entrenched mental models that treat consumers as passive buyers and agriculture as mere market transaction. Community-Supported Agriculture (CSA) offers a locally grounded model in which producers and consumers share the risks and benefits of production, holding potential to challenge these structures and foster new relationships and behaviors that contribute to systemic food system change. However, CSA remains underdeveloped in Japan, and how participation motivations are relationally generated through design remains poorly understood. This study examines how design interventions can cultivate relational motivation: forms of engagement arising through social connection and shared values rather than individual preference alone. A Research through Design (RtD) approach was employed to examine a collaborative design intervention in Isumi, Chiba, Japan (October 2025). It followed five phases: (1) educational sessions on CSA and natural farming, (2) a chef-curated meal featuring locally grown produce, (3) a farm field tour, (4) a facilitated Philosophy for Children (p4c) dialogue, and (5) a co-creation workshop. Eleven participants attended, supported by eight collaborators including a producer, a chef, local staff, and researchers. Pre- and post-intervention questionnaires (seven-point Likert scales) and thematic analysis of dialogue and workshop data were used for analysis. Quantitative analysis (Wilcoxon signed-rank test) showed a significant increase in participants’ ethical food-selection intention (p = .046, r = .63), and eight of ten reported increased willingness to join CSA despite half having had no prior awareness. Thematic analysis identified three themes: deepened understanding of natural farming, intergenerational responsibility for food culture, and critical reflection on production structures. These themes were translated into concrete CSA visions in the co-creation workshop. Through RtD, the study derived design principles for an entry-point intervention to cultivate participation intentions toward CSA: (1) sequential integration of learning, experience, and reflection; (2) cross-domain intermediary collaboration as social infrastructure; and (3) embodied and relational ethics that translate abstract values into situated action. These principles offer actionable guidance for designers, educators, and policymakers seeking to lower barriers to CSA participation within local communities.</p>