The spirit of haikai has always been subversive. In poetry haikai began as an underground movement, motivated by a desire to explore the forbidden, to ridicule the established, and to tear down dogmatic rules and conventions. At times it has been humorous and witty; full of parody and word-play, but at times it has become a serious search for ever new ways to understand our existence; a struggle to overcome the limitations imposed on us by tradition and habits. Unfortunately, popular belief as well as much serious scholarship has it that haikai is rule-bound, conservative, and stuck in tradition. Japanese culture is all too often supposed to be backward-looking and reverent of the past. One important aim of this study is to challenge such views, to show their shortcomings and replace them by more fruitful descriptions. Its main focus is on a number of theoretical works written in the eighteenth century and makes a detailed discussion of the poetics developed in these. It is a study which may be of interest for those looking for a new and fresh approach to this kind of poetry, an approach which at the same time comes closer to the original haikai spirit.