Motivation is an important topic among language teachers in Japan. Collins and Hunt (2011) observed increases in Japanese university student's motivation as a result of collaborative learning and cooperative learning programs. This paper continues in this line of inquiry through a quantitative study of motivation in the context of computer supported collaborative learning (CSCL). Results of this study confirm the motivational profiles of successful collaborative learners and reveal friendship and reciprocity as important social dynamics affecting Japanese collaborators. Contains an English and a Japanese version of the Collaborative Inquiry-Based Project Questionnaire.