Gally in the Japanese original, she is the main character in the story.
Brought up in an extremely violent environment, mutilated when a little child, Yoko was a Martian-born Panzer Kunst agent who used to be a deadly terrorist, responsible for maddening the super computer Melchizedek and killing 450,000 people. Captured and judged by the régime on Earth Orbitary Federation, the lethal agent was once again dismembered and then thrown alive into Earthy atmosphere, remaining in hibernation for more than two hundred years.
Amnesic, she is found by the cyberphysician Daisuke Ido; she is renamed Alita (after Daisuke’s dead cat), and becomes a hunter-warrior, a motorball champion, a tuned agent (facing exterminatory doppelgängers - the thunds) and is trapped by the ingenious but insane Desty Nova. Resurrected in Tiphares, she goes to Ketheres, initially interested in finding her friend Lou Collins’ brain, but she ends up involved in an unorthodox tournament, the ZOTT, where she outbraves a series of unconventional creatures.
Back to Mars after the tournament, Alita will have to face her most intimate ghosts.
[In some European editions, as for example French, the original name Gally is preserved; the same happens with the Brazilian edition.]
Alita wearing four different bodies, in chronological order: berserker body, motorball body, second civilian body, tuned body; Yoko about to attack Melchizedek; Yoko on trial; Daisuke Ido finds the cyborg in The Scrapyard.
Note: Alita is the Arabic name of the goddess Venus. It seems there is a lack of information from American translators here, since she is Martian. Gally sounds to me as a feminization of Garry, an English name meaning spearbringer. As an English verb, gally means frighten, terrify.