- "Too bad cats don’t bake cookies, but I have some good memories of chasing mice."
- —Diana, "Black Dream Hole"
Diana is an adorable and pretty talking grey kitten with a crescent moon on her forehead. She is Rini's companion, and the daughter of Luna and Artemis from the future. She appears in Sailor Moon R and Sailor Moon Super S.
Diana's first appeared in Sailor Moon R when the Pretty Guardians travel to the future.
Diana's appeared in Super S, her first being in Episode 6, Much Ado About Kitten. Every time Fish Eye saw her (which really only happened twice, the first time in the episode Phony Fairy, and the second time in the episode A True Reflection), she would freak out, as she hates cats.
Diana always seemed clueless as to what was going on.
Diana is very loyal. She briefly assisted Sailor Pluto in guarding the door of Space and Time.