Pikapika is a collaborative solo performance by Bahn and Hahn that presents a simple model of composition, choreography and collaboration in an interactive context. The piece offers the possibility of a new kind of interactive theatre/costume design –an interactive sonic character. This essay is a case study of a design process for interactive performance. While we include some details of our specific interface, these are primarily employed as examples to suggest our principles for creating personal, idiosyncratic interactive systems. Our collaboration integrates elemental sound and movement relationships with an awareness of the embodied cultural knowledge of the performer and with a specific sensing scheme to capture her particular gestural vocabulary. The combination of individual ‘atoms’ of movement and sound leads to a complexity that must be practised until they can be performed with ease as an embodied interaction. We find the process of collaboration and its articulation as a dynamic interactive structure fascinating and enduring beyond the specific technologies employed. The terms meta-composition, composed instrument and composed character are used to describe the interactive structure of the piece.