This book explores how learners’ personalities influence foreign language learning in Japan. In particular, this volume investigates three main research questions: What are the learning strategies generally employed by Japanese college students? What are the characteristic learning strategies of extroverts and introverts? Do extroversion and introversion have an impact on English listening proficiency? In the analysis carried out in the volume, both quantitative and qualitative research methods have been used. As regards the former, various types of questionnaires have been employed, measuring strategy use, personality characteristics, and English proficiency. As regards the latter, the strategies students use both in the classroom and in a tutorial learning situation have been observed, integrated with interviews with the students themselves regarding their use of learning strategies. In the last part of the book, the pedagogical implications of this study are examined with suggestions for both teachers and learners.