Never as keenly as during the war-torn sixteenth century was Japan’s warrior class concerned with the possible, sudden destruction of families. The center of everyone’s existence in society, families were really a sprawling institution combining blood-relatives (the house-head and his wife, his parents, and his heir) with marriage relations and hereditary followers. Although retaining the allegiance of affines and retainers was as challenging as besting rivals on the battlefield, a family’s consanguineous core was supposedly as stable as its outer edges were everchanging. Yet (among other contradictions) heirs were routinely adopted from non-kin, at once complicating the meaning of family and opening views on contemporaries’ understanding of members’ investment in such organizations. My project asks: What did it mean to be part of a family?