Diana is the female cat on the hit manga/anime Sailor Moon.
She is the daughter of Luna and Artemis, the two cats who help guide the Inner Sailor Scouts and acts like an advisory of some sort to Chibiusa/Sailor Chibi Moon like her parents are to the other scouts. Because of her young age she is always poking her nose in things, trying to get an idea of whats going on all the time and hates to be excluded from anything that her parents or Chibiusa are involved in and at most times even has valuble information the scouts because of her knowlege of the future.
In the manga, she first makes her appearance when the Sailor Scouts make their way to the 30th century, and there is also revealed to be the child of Luna and Artemis. Also in the manga she does return to the 20th century with them to learn from her parents and scouts.
In the anime she doesn't appear till later in the series, and unlike the manga she randomly makes her first appearance by jumping out of the bushes and calling Artemis 'daddy' while curling up to him. This left not only a shocked and confused Artemis but a very upset Luna who assumed he had an affair with another cat. It wasn't until later that Diana came from the future and that both cats were infact her parents.
While Luna is black and Artemis is white, Diana is grey with bright red, almost pink, eyes.
Sailor Moon Super S: The Movie
The third of the Sailor Moon films.