Because boys can't give birth, they are excluded from the rights of adulthood. They are not allowed to live permanently anywhere, and so have to wander from village to village in packs for mutual protection.
The Moon Women is an organization of grandmothers tasked with safeguarding their culture into perpetuity.
A growing number of women are dissatisfied with the social stratification their culture imposes, and are ready to see it overturned.
This Neolithic matriarchy, isolated in a mountain river valley, has no name for themselves other than "women".