The Japanese \u27adverbial particle\u27 wa is usually argued to have topic and contrastive functions. The previous analyses on contrastive function of wa have two problems. First, they fail to account for \u27association with contrast\u27 in complex NP. Second, the notion of contrast has not been made explicit enough to account for an asymmetry between contrasts involving and not involving wa. This paper assumes that the basic contrastive meaning is carried by phonological prominence, and argues that wa interacts with such a contrast resulting in a distinct presupposition, following \u27alternative semantics\u27 of Rooth
