Diana

Diana is a small cat with purplish-gray fur, red eyes, and a red collar hung with a jingle bell. A golden crescent moon sits on her forehead, echoing the mark worn by Luna and Artemis to signal their bond with the Silver Millennium. Her name is a variation of her father's own: Artemis is drawn from the Greek goddess of the hunt and the moon, and Diana stands as that goddess's Roman name.

Diana comes across as little and sometimes shy, yet she is also bold and sharp-minded. In her role as Chibiusa's guardian she proves wise and level-headed, tending toward sensible judgment. Although her parents fret that she knows little about the twentieth century and its rules, such as not letting outsiders learn she can talk, she in fact grasps how to conduct herself in society.

Diana turns up from the future during the SuperS season, crossing into the present both to look after Chibiusa and to gather real-world experience of her own. In the Japanese version she addresses the main cast with the honorific -sama, a mark of deep respect. Unlike her manga counterpart, she is absent from the earlier season that featured Sailor Pluto.