The series takes place in a world (or at least a community) where lesbianism is the norm.I mean, think about it, was the word "lesbian" flat-out mentioned anywhere in the actual show? Everyone seems quite cool with the girls seeming like they all have a crush on each other. Either that, or they all came out of the closet a long time ago, or off-screen.
A male gendercide event happened before the series began.Long enough that they don't talk about it much anymore. Evidence? There were no males shown at all in the scene of hundreds when Chitose was at Comiket. A few males still exist; as seen in the Christmas episodes, they are required by law to donate sperm. (No, not in any dystopia-esque porn way.)
Males are made, not born.The specific way that the gendercide occurred is most likely this. Why? No one has a brother, (Anymore thanks to retcon) the convention had no guys in it, and all the few males are basically the same mostly off screen guys. Apparently, no males could be born. However, somehow, Homosexual Reproduction technology was so advanced that the human race could survive. This means that everyone is born female and only a certain amount end up male, the exact people women would approve of. Thus rendering Anime to be childish or for women since only being approved could someone become male. That's why there were no boys at the playground, or any mention that the school is an all girls school. It's a given!
Males and females live in seperate communities.It's simple enough to explain. In this world, humans evolved as creatures whose males and females live independently of one another in their own tribes, coming together only to mate. These days it is more organized than that.
The characters are the reincarnations of the senshi and co after Crystal Tokyo fell.In addition, a side effect was the gendercide. Usagi did the same thing as her mom did and sent the ones she cared about to the future, 2012 years after the fall. Just think about it...
If Yuru-Yuri gains enough popularity, an actual Mirakurun manga might be createdAs in official, most likely by Namori herself? The genre of "parody/magical girl" might be what would fit best for an actual "Mirakurun" series.
Mikarurun series is based on the memories of Sailor Moon.Apparently, the anime writers heard these stories about these magic girls in the distant past that they wrote about it, fixing the Clark Kenting.