She appears from the future in Sailor Moon Super S. She is the only guardian cat to wear a collar with a jingle bell around her neck. Apparently, she has come to the present in order to not only keep an eye on Chibiusa, but to gain real-life experience. Diana appears to be small, sometimes timid but at the same time brave and smart. Her being Chibiusa's Guardian, she is also very wise and is often very reasonable. Despite her parents mentioning that she doesn't know very much about the 20th century and what she shouldn't do (such as exposing to other human beings that she has the ability to speak), she is well aware of the rules of being in society.