The Independent Curriculum Reform places character strengthening as part of the Pancasila student profile and the student profile of rahmatan lil 'alamin (P2RA), but the practice of character formation in madrassas often takes place outside the classroom through hidden curriculum which has not been widely studied in the context of non Islamic boarding school tsanawiyah madrassas in Muslim minority areas such as Papua. This study aims to describe the hidden form of curriculum in MTs. Muhammadiyah Jayapura and analyze its role in the formation of Islamic character of students. The research uses a descriptive qualitative approach with a case study design; data were collected through a document study of the Madrasah Operational Curriculum (KOM) for the 2024/2025 Academic Year and analyzed through condensation, presentation, and data conclusion drawing following the interactive model Miles, Huberman, and Saldáña (2020). The results of the study show that the hidden curriculum in MTs. Muhammadiyah Jayapura is manifested in thirteen daily habituation practices, Golden Habits digital character mentoring programs, mandatory extracurricular activities (Hizbul Wathan and Tapak Suci), and optional extracurriculars associated with the dimension of Pancasila student profiles. These practices work implicitly and repeatedly to instill the values of worship, morals, discipline, and religious moderation, complementing the formal curriculum of Islamic Religious Education. This study concludes that the hidden curriculum functions as a strategic instrument for the formation of Islamic character whose success depends on the consistency of educators' example and the management of madrasah culture deliberately and planned, not on the existence of a dormitory structure alone.