This study reconsidered educational materials by analyzing educators' opinions regarding handmade manipulative materials (HMMs) for children with profound intellectual and multiple disabilities in Japan. Instead of concurring with the view that educational materials are static and inert products, the author adopted an agential realist perspective and considered them as agencies working and becoming with teachers and children. The author interviewed two retired teachers who had spent more than 30 years in HMM production and analyzed the obtained data using a diffractive methodology. Findings showed that making and remaking HMMs allowed teachers and children to engage with actualizing concepts without language and demonstrated the open-ended nature of learning for teachers and children with HMMs.