Tarakuu and Mejeiru
The home planets of the main characters in the anime series Vandread. Men exclusively populate Tarakuu and Mejeiru is, likewise, populated entirely by women. Apparently some kind of civil war broke out between the two sexes and they both fled to their respective planets to build their own societies and their joint origins were soon forgotten. By the time the main male character Hibiki meets the women pirates they are so estranged from each other that they don’t even seem to realise that they are the same species. Of course that is the whole point of the story which makes it rather amusing to watch as they gradually find out more about their origins.