This study argues that a view on utterance-final conjunctive particles, based on the notion of implicature, may provide an additional approach to this phenomenon. It employs notions of (im)politeness and interactional implicature to discuss how these particles may produce inferences that lead to several interpersonal and interactional effects. A detailed exploration of projection and uptake of the implicatures in the sequential development of conjointly co-constructed interpretings in Japanese interaction, shows that a better reconciliation of analyst and participant approaches, enables a better understanding of the mutual completion of linguistic and communicative views on implicature.