Japan has become a wasteland devastated by the Rusty Wind which causes all things to rust away. A suspicious looking priest visits a checkpoint all alone, yet on his back rests a bow priests wouldn't use.
Meanwhile, Milo, a doctor running a clinic in the town of Imihama, is researching new medicines in secret in order to save his older sister, Pawoo, who's being corroded by the Rust. But that day a stranger appears before him...
They say you have to 
fight poison with poison,
،يُقال بأنّه لا يقاوم السمّ إلّا السمّ
Gift lässt sich mit Gift unterdrücken,
El veneno se neutraliza con veneno.
El veneno se neutraliza con veneno.
Dicono che bisogna contrastare
 il veleno con il veleno,
Dizem que você precisa 
combater veneno com veneno,