The Sound of Rust (Episode 23)

The Sound of Rust is the twenty-third episode of the anime series.

Synopsis
A girl is ostracized by her village because, according to a rumor, she is the cause of a strange rust that afflicts the houses and people there. Now it's up to Ginko to figure out the truth.

Plot
Arriving at village, Ginko see more red rust covering buildings and people alike. He consults with the chief, who tells him that an incurable sickness has plagued this village for 14 years. People’s skin becomes hard and they eventually stop being able to move their limbs. The townspeople blame a girl who stopped speaking named Shige, as the people started to get sick ever since she was born.

A boy named Tetsu helps Shige collect a spilled bag of food and she thanks him silently. Shige returns home, where her parents are bedridden, covered with rust. Ginko arrives and tells Shige that he knows she could see the rust. He says that he could treat the sickness and asks her to tell him more. He fills a room with smoke where could talk freely without getting sick. Shige tells him that her voice still creates rust even after it became deep and cracked because she kept screaming in the cave, back on the mountain. When she was 4, Shige had confided to her parents, who could not work anymore because of the rust. They told her to keep it a secret and stop talking as they live off of the chief’s kindness. Ginko takes out a jar of rust he collected earlier and explains that her voice resembles the sound of the mushi “Yasabi”. The Yasabi gathered because they expected food when they heard her voice and attached to the living when there isn't. Ginko tells Shige they can get rid of the mushi using her voice. Shige agrees and asks to learn how to write.

Ginko that there’s no Yasabi on Tetsu, alongside a breeze that came from the ocean. Shige returns the face cloth from before to Tetsu and gives him a letter before running away. A villager takes the letter which reveals Shige's the cause of the sickness from Tetsu and read it aloud. The villager tries to go tell the chief but Tetsu burns the letter. Ginko overhears the villagers. After he and Tetsu arrives at Shige's house, Ginko tells Shige and Tetsu to wait on the mountain pass, where he will tell her how to rid the mushi while he stays to deal with the angry villagers. The villagers arrive at the house and demand Shige to pay, but Ginko convince them that Shige could make things even by ridding the sickness.

Shige and Tetsu make their way up the pass but they lip and fall off a steep slope. Shige calls for help by screaming into the mountains. The Yasabi in the village began moving towards the mountains. Back at the pass, Ginko hears Shige and finds them. Shige cries and apologies for getting Tetsu sick too as Yasabi surrounds them. Ginko reassures her that Tetsu's only unconscious and couldn’t get sick from rust. When they returned to the house, Shige’s parents could walk again. Ginko tells her that she did basically what he was going to tell her to do-scatter the Yasabi that gathered in the village by echoing her voice in the mountains on the pass, with the ocean behind it as Yasabi doesn't like salt. He explains that Tetsu never got sick because he grew up by the sea and went home often. Shige has to do this for several years to scatter the Yasabi completely but she could live a normal life by the sea.

After Shige left, the sickness slowly lifted. Villagers say they could still hear a strange but beautiful singing echo through the mountains.