One of a vampire-like race, the Crimson Nobles, she and Loretta make their living stealing and treasure-hunting. She seems to have a slight crush on Sheyanne, though that might be because she (and every other Crimson Noble) finds his blood incredibly delicious. Crimson Nobles have the ability to transform into strange bat-like creatures, and Mirabelle often transforms easily between the two forms, though others have remarked on her slow flying.  (Source: Wikipedia)

This anime is based on a PlayStation game under the same title. The story is about four people who travel the desolated land of Filgaea and carve themselves a legendary story while they`re at it. These adventurers are Sheyenne Rainstorm, a gunslinger who holds the legendary weapon called ARMs; Kiel Aromax, a scientist who looks like he should be carrying a sword; Roleta Oratorio the Crest Sorceress, a magic-user who uses cards called Crests to cast spells; and Mirabelle Graceland, one of the Noble Red, which are a family of vampiric creatures who live alongside human beings They also travel with cute little intelligent furry things, from the Popepi Pipepo Tribe, named Isaac and Jerusha.<br><br>
(Source: AniDB)