Ami Hyuga aka The Machine Girl was a normal Japanese teenage girl until her brother was murderd by Sho Kimura the son of the local Yukuza boss Ryuji Kimura. She goes to see one of Sho's freinds to try to get him to admit to helping kill her brother but he mocks her and leavs, moments later his parents try to kill her, she escapes but later that night she goes back and threatns to kill to the boy unless she tells him who killed her brother, he does so but she decapitates him and kills his mother, she then showers his father in his sons blood. She goes to the Yukuza hide out and kills a few gaurds before being captured and haveing her right arm cut off. She escapes but loses a lot of blood she makes it to a mechanics and has her arm stiched up eventually haveing it replaced with a large machine gun, but as soon as she gets the new arm the Junior High Shuriken Gang attacks and kills the owner of the gararge. Ami and the wife of the garage owner Miki kill the Shuriken Gang and go on a bloody rampage until they eventually come face to face with the Kimura family, after a bit of trouble with the mother and her Drill Bra she finally kills her and Sho, sadly Miki dies so she continues to kill other members of the Yukuza and other bullies.