In this article, we report on a National Science Foundation-funded immersive international summer research program for biology students. Six students, representing Cohort 1 of a three-year program, spent 9 weeks at one of three institutes in Japan, working on related molecular, cellular, and developmental research projects under the mentorship of a Japanese researcher. We describe the recruitment process, pre-departure activities, orientation week, research projects, and mentorship structure. Data were collected to determine the impact of the program on students' views about science and to seek feedback about the structure of the program. The pre-, mid- and post-program interviews with the students as well as their weekly written reflections revealed that the program challenged their perspectives about science, broadened their understanding of what it means to engage in science research, and contributed to their growing confidence as budding scientists. The students mentioned that certain elements of the program, including the orientation week, weekly meetings, and individualized and hands-on mentorship they received, contributed to their rich experience in Japan. Suggestions are provided for adapting this model to develop other international opportunities for STEM students.