The utopian metropolis of Zalem soars high in the skies, its presence dominating the horizon. Beneath it is the noxious underbelly known as The Scrapyard, where the city stockpiles all of its waste. Living amongst the vast heaps of garbage are humans and cyborgs, surviving by any means necessary.

Daisuke Ido, a doctor specializing in cyborg repairs, finds the head of a young female cyborg while scavenging a pile of old android parts. Proceeding to build her a new body, he names her Gally. Upon activation, Gally does not seem to remember anything about her past life. Nonetheless, she does not seem to mind as long as she stays by Ido’s side.

However, she soon discovers that Ido has a side job as a hunter-warrior, a bounty hunter working for The Scrapyard’s government. Despite Ido’s warning, she decides to become one herself, awakening her forgotten knowledge of fighting techniques. Equipped with newfound strength, Gally is determined to fight through the alleys of The Scrapyard and beyond, retrieving fragments from her past to rediscover her true identity.