This study examines how diaspora, local wisdom, and reciprocity shape the development of Islamic education within the transmigrant Nahdlatul Wathan (NW) community in East Kalimantan. It addresses three questions: how reciprocal relations with the local community develop, how those relations shape educational cultural capital, and how educational agency and institutional structures reproduce reciprocal values. The study employs a qualitative approach with a religious phenomenology design at three loci: Kutai Kartanegara, Paser, and the city of Samarinda. Data were collected through semi-structured in-depth interviews, open observation, and documentation, then interpreted through phenomenological reduction combined with an interactive process of data condensation, data display, and conclusion drawing and verification. The findings show a shift from generalized reciprocity, in the form of mutual assistance, voluntary work, and solidarity, toward balanced reciprocity through the exchange of educational services, religious outreach (dakwah), social acceptance, trust, land, and institutional support. The potential for negative reciprocity arises over issues of land, authority, and interests, but it is generally managed through deliberation (musyawarah) and local wisdom. Reciprocal relations also transform religious habitus and social trust into embodied, objectified, and institutionalized cultural capital. The sustainability of NW education depends on the recursive relationship among knowledgeable actors, organizational rules, and mobilized resources. This study proposes the concepts of educational diaspora reciprocity and reciprocal structuration of education to explain how migration experiences are transformed into adaptive, multiethnic, and sustainable Islamic educational institutions.