This volume brings together papers that take usage-based approaches to study the nature of human language, with a focus on the grammar of Japanese. The 12 chapters provide a rich array of data and methodologies, with topics ranging from phonology, modality, and grammatical morphemes, to sentential construction and discourse-level phenomena such as turn-taking, speech register, and language change. As a whole, they demonstrate that usage-based linguistics illuminates various phenomena in the language that could not have been well accounted for by resorting solely to a formal theory such as the Universal-Grammar-based approach. Reflecting theoretical, methodological, and technological advancements made in and outside the field of cognitive-functional linguistics in recent years, the papers contained in this volume, both individually and collectively, have significant implications towards linguistics in general and Japanese linguistics in particular.