The Demon Doctor

This is a story of female Akaza who when turned into a demon kept her memories and instead of killing and becoming an uppermoon, instead went on to treat the sick sense she couldn't do that for her father and Koyuki.

Things you'll need to know:

Akaza will go by Hakuji

Akaza's demon blood art will be different its now that she can extract poison from things then by touching a sick person then the poison turns the poison into a medicine

Some hashira can be dicks

Akaza treats both human and demon she doesn't discriminate

Akaza and Koyuki felt like sisters instead of lovers