While neither the anime or manga elaborate on the planet, one can assume that the inhabitants are essentially "Cat People", who are able to take on the forms of both talking felines, and humanoids with feline features.
- Diana is the only talking feline in the anime or manga that does not come from the planet Mau and was born on Earth.
- All three guardian cats appear as humans at one point or another in the manga while in the anime the only one to appear in human form is Luna in Sailor Moon S: The Movie.
Sailor Tin Nyanko is also said to have come from Mau, and it is implied that during Sailor Galaxia's conquest of the galaxy, Tin Nyanko killed Sailor Mau, Mau's Sailor Senshi, and took her Star Seed in order to win Galaxia's favor. The planet was eventually devastated by Shadow Galactica.
Mau was a planet in the Milky Way Galaxy.