Milo, a doctor, searches for medicines to cure his older sister who suffers from the effects of the Rusty Wind, which has turned Japan into a rust-filled wasteland.

Akaboshi Bisco causes havoc in the town of Imihama; Bisco searches for a doctor who can save his mentor.

Bisco and Jabi continue their journey through Touhoku in search of Sabikui, the Rust-Eater, the sacred mushroom that is believed to possess the power to cleanse.

Milo and Bisco head to Tohoku in search of the Rust-Eater. Milo struggles with his training to ride the giant crab Actagawa.

Milo teaches the children of Tetsujin Town how to make a cure for Shellskin. Pawoo helps a couple from a giant spider's attack, without knowing their plan to kill her.

Bosco and Milo receive help from Tirol after they rescue her from the brink of death. Pawoo carries on with her relentless chase.