In this study, based on both historical evidence and ethnographic data, Paula Arai shows that nuns were central agents in the foundation of Buddhism in Japan in the sixth century. They were active participants in the Soto Zen sect, and have continued to contribute to the advancement of the sect to the present day. Drawing on her fieldwork among the Soto nuns, Arai demonstrates that the lives of many of these women embody classical Buddhist ideals. They have chosen to lead a strictly disciplined monastic life over against successful careers and the unconstrained contemporary secular lifestyle. In this, and other respects, they can be shown to stand in stark contrast to their male counterparts.