This study aims to analyse santri character education in peripheral pesantren by using the thought of KH. Hasyim Asy’ari as an interpretive lens. The study is motivated by the limited empirical research on character-education practices in peripheral pesantren and the underuse of the concept of adab as a contextual analytical framework. A qualitative descriptive–interpretive approach was employed, using a multi-site design across several pesantren in Muara Wahau District, East Kalimantan. Data were collected through in-depth interviews, participant observation, and documentary study, and were then analysed thematically through data reduction, data display, and verification. The findings indicate that character education in peripheral pesantren develops as an adab-based praxis system integrated within collective life. The values of discipline, independence, responsibility, simplicity, and social concern are internalised through the kiai’s exemplarity, disciplinary habituation, and intensive pedagogical relations. These findings affirm that adab functions as both a moral foundation and a pedagogical infrastructure that continually reproduces the habitus of santri character. This study formulates a contextual, praxis–cultural, adab-based model of character education for peripheral pesantren, offering a relevant alternative to character-education approaches that are normative–administrative in orientation.