Intercultural adjustment of Japanese high school students who sojourned in the United States for one year is the focus of the study. Building relationships with host nationals using limited English competency is the challenge that seems basic to successful adjustment to life in the USA. A path model was constructed in which English competence leads to better social skills, which in turn affects the amount of social support gained from host nationals. This model was tested through structural equation modeling, and the model's fit to the data was satisfactory. The predictive roles of English proficiency and personality were suggested in a supplementary analysis.