A small but important set of studies on complaint speech acts have been focused on certain aspects of native speaker (NS) and non-native speaker (NNS) complaints such as strategy use and native speaker judgment, (Du, 1995; House & Kasper, 1981; Morrow, 1995; Murphy & Neu, 1996; Olshtein & Weinbach, 1987; Trosborg, 1995). However, few researchers have comprehensively researched complaint interactions. Complaining to the person responsible for the complainable (as opposed to complaining about a third party or situation) is a particularly face-threatening speech act, with social norms that vary from culture to culture. This study was an investigation of how Japanese and Americans express their dissatisfaction to those who caused it in their native language and in the target language (Japanese or English). The data analyzed are from the role-play performances of four situations by ten dyads in each of four groups (native speakers of Japanese speaking Japanese to a Japanese (JJJ), native speakers of English speaking English to an American (EEE), native speakers of Japanese speaking English to a native speaker of English (JEE), and native speakers of English speaking Japanese to a native speaker of Japanese (EJJ). The complaint categories used in this study represent a pared-down version of Trosborg's (1995) categories based on two criteria: (a) hinting or mentioning complainable and (b) negative assessment of the complainer's action or of the complainer as a person. The following characteristics of the complaint interactions were analyzed: (a) the length of interactions in terms of the number of turns, (b) complaint strategies used by complainers, (c) initial complaint strategies used by complainers, (d) the comparison of S1Hint and S2Cmpl as the initial position, (e) interaction flow in terms of complaint severity levels, 6) strategies employed by complainees, and (f) flow of complaint interactions between complainers and complainees. The results indicate some differences between the groups of native speakers of English and Japanese in the length of their interactions and the use of strategies by complainers and complainees. In general, complaint sequences in English were shorter, and the complaint strategies used by the JJJ group were less indirect than those used by the EEE group. Several prototypical complaint sequences are described. Concerning the use of strategies, the JEE and EJJ groups used strategies more in line with those employed by target language speakers, rather than by speakers of their own language. An attempt is made to account for the different characteristics of English and Japanese complaints in terms of linguistic resources. Pedagogical implications are also highlighted. / CITE/Language Arts