Basically it takes place in a world where men don’t exist, just women and futa. If a futanari works out hard and heavy on a regular basis she massively bulks up, her body gets taller to accommodate the increase in muscle mass, and the hormonal changes cause her cock and balls to start growing. And futa milk or cum (not really sure which) acts as a steroid when drunk by “normal” women, more so the bigger the futa it came from was. So the story is about a gigantic bodybuilder helping her girlfriend when she decides she wants to start growing too.
