Battle Angel Alita, called GUNNM (銃夢 lit. juu (gun) mu (dream), creatively read as ガンム ganmu) in Japan and Europe is a manga series created by Yukito Kishiro in 1991 and published in Shueisha's Business Jump magazine. The title translates to "Gun Dream", and the nine-volume comics were adapted into two anime original video animation episodes titled "Battle Angel" for the North American release by Viz Media. The manga series is continued in Battle Angel Alita: Last Order.

Battle Angel Alita tells the story of Alita ("Gally" in the original version), an amnesiac female cyborg. This cyborg's intact head and upper torso are found in a state of suspended animation by the cybermedic expert Daisuke Ido while he's out searching for useful scrap. Amazed by his discovery, Ido quickly returns home and works to revive her. Upon finding that the girl has lost her memory, Ido names her Alita, the name of his recently deceased cat.

The rebuilt Alita soon discovers that she possesses instinctive knowledge of the legendary Martian martial art Panzer Kunst, although she has no other memories of her previous life. Alita must learn to navigate, exist, and fight in the Scrapyard, whose inhabitants themselves live in the rubbish of the tantalizingly close floating city, Tiphares.

Ido builds Alita a new cyborg body, but she begins to suspect that the parts have been obtained from a series of murder victims. She follows him one night, hoping to discover the true nature of his midnight activities. She watches him lie in wait for what appears to be an approaching woman, and intervenes. The woman turns out to be a berserk mutant woman with a bounty on her head. She attacks Alita and Ido.

Alita fights the woman, and suddenly delivers a killing blow. Ido recognizes the technique as an ancient Martian martial art known as Panzer Kunst ("armored arts"). Ido reveals that he is a hunter-warrior, or bounty hunter, and Alita decides to become one as well. This begins Alita's quest to discover her true identity. Her journeys take her across the Scrapyard and surrounding areas, as she tries to recall more of her past.

From Wikipedia