This article is based on fieldwork among the Guajá people, a small indigenous group of Tupí-Guaraní speakers inhabiting the eastern portion of Brazil’s Amazon region. Aiming for an ethnographic definition of kinship, this article engages in issues related to the figure of the “owner/masterin the Amazon, proposing a dialogue with a seldom discussed aspect of this subject—namely, its relation to conjugality. I argue that relationships included in the universe of “familiarity” and “mastery” are not only coextensive with the field of kinship; they also reveal a very particular conception of humanity. The process of Awá-Guajá kinship, where the spouse is transformed through a very particular system of actions, can only be understood if we move b...