The purpose of this study was to describe how Japanese undergraduate students engage in learning in a physical activity basic instruction course, specifically, flag football. The study was situated in the framework of andragogy theory and used an explanatory (holistic) case study design. Participants were five Japanese undergraduate students with no prior experiences of learning flag football at a public university. Data sources included ten weeks of individual weekly journal reflections. A constant comparative method was adopted to interpret the data. Three emergent themes were: (a) "problem-solving based learning," (b) "the importance of reflective, cooperative, and collaborative learning," and (c) "application of flag football knowledge outside of class." To better support Japanese undergraduate students' learning experiences in the course, we encourage faculty and students to learn how to develop a blueprint of flag football, game strategies, and performance analysis that enables them to capture the nuance of content learning through problem-solving experiences.