The film follows Ruka as she tracks down and kills engineers, who are responsible for the death of her father. Along the way, she joins forces with a group of rebels who are fighting against the corrupt privatized police force.
The engineers are mutated individuals with various abilities, including the ability to spew acid and transform their bodies into deadly weapons. They are also immune to traditional forms of weaponry, forcing Ruka to rely on her samurai sword skills to take them down.
As Ruka delves deeper into her quest for revenge, she begins to uncover a sinister conspiracy involving the privatized police force and the engineers, and must decide whether to continue her mission alone or team up with the rebels to take down the entire corrupt system.
The film is known for its over-the-top violence and gore, often featuring outrageous weapons and deaths. It also contains social commentary on the privatization of law enforcement and the rise of self-mutilation as a cultural phenomenon.