Streaming: Funimation and Crunchyroll
Episodes: 12
Source: Light Novel
Episode Summary: After a disaster destroys Tokyo and turns it into an inhospitable desert, people begin to die from a mysterious illness known as the “Rust.” It slowly overtakes their bodies until it reaches their hearts. There are theories regarding how the illness is spread, some of which involve the assumption that strange plagues of mushrooms (and the mushroom keepers who create them) are somehow responsible. The most notorious of these mushroom keepers is Bisco Akaboshi, who spreads terror using his bow and arrows to produce giant mushrooms.
Doctor Milo Nekoyanagi maintains a residence in the slums where he tends to the impoverished locals while also using connections to obtain contraband mushroom material in order to search for a cure for the Rust. His motivations seem rooted in kindness, but they have a selfish angle as well – his sister Pawoo is suffering from the disease. One evening, none other than Bisco makes his way into the city to wreak havoc, causing the pavement to burst forth with mushrooms with every strike of his arrows. But he seems focused on one mission in particular – to seek out Doctor Nekoyanagi.
