Study abroad (SA) has recently become an increasingly popular option for language learners who wish to engage in an immersive educational experience while living in a different culture, but not all SA programmes are created equal. Length of time can vary significantly, from a days or weeks up to a year or more spent in the target culture, and this can affect not only linguistic development but also non-linguistic factors such as intercultural communication, confidence using the second/foreign language (L2), and a sense of L2 self. The purpose of this study was to examine how two groups of Japanese learners of English going abroad for different lengths of time (one month (n = 79) and one year (n = 70) respectively) were affected across a range of non-linguistic variables. Pre- and post-SA survey data were collected, and results indicate that both groups achieved significant benefits in increased L2 speaking confidence and a strengthening of sense of an ideal L2 self, while also undergoing a weakening of ought-to L2 self. However, the degree of change was not uniform across groups. Moreover, the short-term SA participants demonstrated a decrease in ethnocentricity whereas the long-term participants did not.