Diana the Moon Fairy is an unused character who was originally proposed for the manga but never appeared in it. She only appeared in the Materials Collection, the sixth and final artbook.
Diana is described as being "as fragile as a teardrop". She has thin, light blue wings and wears a short lemon-yellow lace dress. Diana also dons star and moon earrings and bracelets and wears her blonde hair in odangos like Usagi.
Naoko Takeuchi noted a few details about Diana in the Materials Collection; she was cute, talkative, impertinent and playful.
In the original storyline, Sailor Moon and the Inner Sailor Guardians found Diana among the ruins of the Moon Kingdom. In the actual storyline, the five senshi found a winged Queen Serenity.