The emotional aspects of language have so far not received the attention they deserve. This study focuses on nonpropositional, i.e. expressive and interactional meanings of Japanese signs, with special emphasis on understanding their cognitive, psychological and social meanings. It shows how the Japanese language is richly endowed to express personal voice and emotive nuances, and confronts the theoretical issues related to this. The author proposes a new theoretical framework for Discourse Modality, a primary concern for Japanese speakers, to analyze the 'expressiveness' of language.