While, today, reflexivity is mainly oriented towards the persona of the anthropologist, the role of one’s emotions and their effects on fieldwork and the restitution of results, this article reverses the perspective by focusing on the women and men who allow the anthropologist to penetrate into microcosms to which they did not necessarily belong, and which always constitute, in a certain manner, another door of entry into their society and, more largely, their lives. Traveling companions, mediator-collaborators, close or even intimate friends, these individuals have varied profiles and motivations which are explored here through accounts from several French and Asian research projects. The hermeneutical relationship woven day-to-day in the face of obstacles to the investigation seals a specific bond that shows the weight of politics along with the epistemological issues that characterize mediation in anthropological knowledge.