This study examined changes in English as a second language (ESL) speakers’ identities and in their attitudes toward speaking English, based on the responses provided by 75 Japanese students attending college in the United States (U.S.). Analyses of their responses revealed that the more time those ESL speakers spent in the U.S., the more they became in favor of speaking English in their own way, experienced a positive transition between different identity types, and felt either prouder or less proud of their identity as Japanese. The study results also suggested that two to three years in an English-speaking country or environment might mark a turning point for many ESL speakers’ attitude and identity changes. Furthermore, those who had only a short-term ESL learning experience before being mainstreamed into college were more likely to experience a transition earlier during the four years of college than those with a long-term ESL learning experience.