The butterfly girls have a specialty in medicine and healing. They are adept at managing injured demon slayers and helping them recover to return to the battlefield again. Most of the healing is done by Shinobu. Then Aoi designs the rehabilitation and training regime. Naho, Kiyo, and Sumi help Aoi implement it. Once a demon slayer has been through all the stages and is filled with love and care from these beautiful young hearts, he is sent out to slay another demon.