This paper explores phases of peer relations between Japanese Bolivians and non-Japanese Bolivians(grades 1-8) at an ethnically mixed school located in the Republic of Bolivia. At the school, studies consisting of participant and systematic observation, structured and semi-structured interviews, and a questionnaire were conducted several times between 1994 and 1997. There were 55 Japanese Bolivians and 109 non-Japanese Bolivians at the school in 1997, when the main data for the paper were gathered. The author noted that Japanese Bolivians had Japanese classes and, through the classes, shared various experiences. Not all the shared experiences revolved uniquely around Japanese culture, but the classes and shared experiences furthered communication and other activities within the group. The experiences reinforced the solidarity of the Japanese Bolivians and separated them from the non-Japanese Bolivians. That is to say, the shared experiences of the Japanese Bolivians created further boundaries between the ethnic groups.