This paper is an investigation into the impact of a hierarchal and exclusive ability grouping framework on the self-perception and mathematical identity of diverse students in Aotearoa, New Zealand. Research interest in the low achievement of certain groups of students is growing as a result of increased understanding of the impact of cultural and societal norms. However, there has been less research into factors that influence how to support student perception to promote effective learning. This case study examines how perceptions of ability can be viewed as either exclusive or inclusive, and how this can be used to capture and cater to the complexity of a student's identity as a mathematician.