SLA literature tends to focus predominantly on what motivates language learners, but what demotivates them has not been widely discussed. This book, focusing exclusively on demotivation, will help readers to understand motivational issues from a different perspective. The aims of the work are threefold: to present the current developments of demotivation research in the field of SLA and bridge motivational theory/research and demotivation research; to promote the understanding of possible causes of demotivation; and to expand the focus of demotivation research through a reflection on current motivation theory/research and a discussion of methodological issues. The research presented in this book is situated in Japanese English-teaching contexts and will serve as a foundation for anyone wishing to better understand the causes of demotivation in SLA and to explore the topic in their own contexts.