Previous studies of language and gender discuss how men and women use gender-specific conversational styles mainly in relation to English, whereas similar studies for Asian languages remain comparatively few. Moreover, little is known about gender and conversational styles during intercultural communication. This paper explores whether speakers follow similar norms of politeness in mixed-sex talk in their L1 and in intercultural conversations in L2 English, and if femininities are modified, what factors may be involved. It reports findings from a case study of a Japanese female’s conversations with a Japanese male in Japanese and with three male L2 English speakers. It suggests that femininities might be modified to become more ‘immodest’ in English due to factors such as speakers’ varying level of adherence to native cultural norms in L1 and in L2 contexts and the male interlocutors’ ethnicity. For example, female speakers who adhere to native cultural norms in L1 conversations may see L2 intercultural contexts as opportunities to create non-traditional femininities, especially when there is no male interlocutor with shared ethnicity. The construction of L2 femininities may also be shaped by linguistic factors such as L2 proficiency or systemic differences between the two languages.