Gerrit is a private sperm donor from Hamburg who has fathered 30 children with lesbian couples across Germany, on one condition: total openness about biological origin. The film follows Gerrit, his wife, and his three sons as they host the annual "herd meeting," a weekend gathering where all the donor-conceived children and their mothers convene at his house, the kids romping through the garden with half-siblings they have grown up knowing rather than discovering later in life. Interviews with several of the mothers lay out why they chose a known donor over an anonymous clinic, and what it took to negotiate a network this large, from custody expectations to how much involvement Gerrit has in each child's life. Gerrit's own sons talk about what it is like to share a father with two dozen half-siblings they see every year. The documentary treats the arrangement as a working alternative family structure rather than a curiosity, following the practical mechanics of how it holds together year after year.