This study was initiated in order to understand how cross-cultural friendships are formed and managed by non-native and native Japanese university students in Tokyo. In order to examine the impact of culture upon the formation of friendships, case studies were employed. Data were collected using ethnographic tools, such as participant observation, informal interviews and unstructured interviews with five participants. Individuals were categorised into two groups: Case A - those who were satisfied with their friendships and Case B - those who were dissatisfied with their friendships. Each case was examined using the framework of acculturation (Berry 2006). Through analysing patterns existing amongst and between Cases A and B, I identified what makes it challenging for university students to form cross-cultural friendships. Case A participants seemed to maintain an equal power balance between 'my culture' and 'other cultures'. They gained new interactive competences appropriate for cross-cultural contexts, whilst maintaining their own core beliefs and values. Case B students, on the other hand, struggled to understand how to bridge a gap with others in cross-cultural contexts. They also found it challenging to fit into a 'group culture', which was demonstrated in this particular research field of the Japanese university. Throughout the interviews, a link between language and culture was also identified.