This article reports on a case study of Miho, a Japanese high school teacher, exploring her efforts to bridge research and practice in her use of motivational strategies. Drawing on Emirbayer and Mische's conceptualisation of agency and Connelly and Clandinin's theorisation on teachers' personal knowledge, the study examined how this language teacher-researcher developed her agency as she strove to integrate motivation strategy research into teaching practice. The narratives of Miho's experience were gathered over three phases: (1) an enrolment phase; (2) a retrospective phase/the follow-up retrospective phase; and (3) an overview phase. The analysis of the collected data focused on Miho's experience of becoming an agent of using motivational strategies. The findings suggest that the more experience she accumulated through trial-and-error use of motivational strategies in different educational contexts, the better she became at absorbing what she had learned from her research engagement, and the better she found herself able to make full use of strategies learnt in the classroom.