Leena is a character in the anime Zoids/Zero, produced by Xebec and shown on TV Tokyo.
Her full name is Leena Touros (alternate spelling Toros) only in the English dub, however. Her name is Rinon in the original Japanese version of the show.
She is daughter to Dr. Steve Touros, the owner of the Blitz Team, and sister to Leon Touros, one of their former pilots.
She is characteristic of a redhead in anime, having a very aggressive and fiery personality, but being really soft on the inside (see also: Asuka Langley Sohryu (Neon Genesis Evangelion), Rika Nonaka (Digimon), Leena(Chrono Cross)).
Leena is the subject of a crush (if that can be the right word to describe it) from Harry Champ, the stereotypical rich, pretty boy character, but has no liking of him whatsoever.
The pairing between Leena and the main character Bit Cloud is the most common when it comes to Zoids fanfiction, pretty much eclipsing all other pairings. In the show, however, there is no evidence of her either liking or hating Bit, but that is another discussion altogether.