Celi Rivera's life swirls with questions. About her changing body. Her first attraction to a boy. And her best friend's exploration of what it means to be genderfluid. But most of all, her mother's insistence she have a moon ceremony when her first period arrives. It's an ancestral Mexica ritual that Mima and her community have reclaimed, but Celi promises she will NOT be participating. Can she find the power within herself to take a stand for who she wants to be?