Propagule (Kimetsu no Yaiba)

When a Blood Demon Art turns all the Hashira into cats and forces them into hiding, all your expertise as the Butterfly Estate's veterinarian and biochemist is redirected into three objectives.

1) Protect the Hashira.
2) Finish the anti-Kibutsuji drug.
3) Track down the demon who cast the Blood Demon Art. And kill them.

Tamayo graciously allows you and the Hashira to take refuge in her home in Asakusa, hiding from demons stalking across Nihon on the hunt for the Corps' strongest slayers. Unfortunately you, too, have your ghosts. And they live in Asakusa.

Without the Hashira, the organization is weak, and Kibutsuji Muzan smells blood. While the Demon King musters his forces to wipe out the vulnerable Corps once and for all, you're racing against time to undo the Blood Demon Art and complete the anti-Kibutsuji drug, and you have to do all of it before the demons - and your past - catch up with you.

Good thing you're fast. And so are your nine cats.

TL;DR: The Hashira turn into cats. Shenanigans ensue. Fluff. Crack. Angst. The fanfic writer's starter set, now with original worldbuilding :)

Please refrain from posting any explicit guesses as public comments until the full story is up, as that will unfortunately spoil my elaborate and evil plan, but feel free to DM.

Weekly updates. Reposted on AO3 and Quotev. Cover by Beedos!