This study examines the self-perceived speaking proficiency development of 204 learners of Japanese who studied abroad in Japan and analyzes connections between self-reported social network development, language use, and speaking development. Learners perceived that they gained the most in areas associated with the intermediate and advanced levels of the ACTFL (American Council on the Teaching of Foreign Languages) Speaking Proficiency Guidelines and the least in novice and superior-level abilities, largely because of a ceiling effect--learners were highly capable of novice-level tasks before study abroad and therefore had little to gain. Regression analysis indicated that self-reported pre-departure proficiency level, dispersion (number of social groups in which a learner participated), time spent in Japan, total time spent speaking Japanese, time spent speaking with native-speaker friends, and time spent speaking English with native speakers of Japanese predicted 44.6% of the variance in the perceived gains of study abroad in speaking proficiency. Self-reported pre-departure proficiency level and time spent speaking English with native speakers of Japanese were negative predictors. (Contains 3 tables.)