The aim of this study was to assess moment-to-moment occurrences of Japanese language learning (LL) anxiety symptoms in a university classroom by evaluating the relationship between self-reported affective states and heart rate measures. Over a period of three sessions, undergraduate Japanese language students (5 males and 5 females, mean age = 19.7 years, SD = .95) wore Fitbit smart watches and performed a class-observed dialog while seated at their desks. Students were also asked how they were feeling at three intervals within each session: class start, pre-performance, and post-performance. Self-reported feelings of distress and embarrassment were found to have significant relationships with HR response. The current study advances the field by providing a new data collection system which effectively assesses affective states in a 'live' classroom setting. Real-time assessment of affective states can assist in identifying when shifts in affect occur, with the potential for these shifts to inform LL interventions.