Here is an exploration of the micro politics of cultural belonging in West Java in the historical experience of one Peranakan-Chinese-lineage community over the duration of the twentieth century. This article examines how that lineage group renegotiated its belonging to West Javanese local society on the three intertwined scales of kinship connections, the provincial cult of Javanese kings, and anticolonial nationalist hagiography. The author combines recent Indonesianist studies to examine how local actors deploy “sites, bodies, and stories” to appropriate nation-endorsed narratives for the construction of local ethnic and religious group identities. The article further traces how Thung-Tubagus actors interchanged their genealogical identity between Confucianist and Javanese cosmologies, and the rise of the Chinese, Indies, and Indonesian nations, while staying rooted to West Java’s locale over time. The process of negotiating genealogical change followed not only a nationalist script but also relied on mutual recognition by the real and fictive kin, as well as by religious gate-keepers of the respective communities on the ground. Analysis at the micro level of genealogical identities reveals a heretofore unexplored provincial element in the constitution of the ethnic boundary between the Chinese and indigenous groups in twentieth-century Java.