He always speaks in a sly, playful tone and smiles without a care in the world. Since his death in the Infinity Castle, he occasionally appears in Shinobu's nightmares.

Due to childhood domestic violence, she is quiet and shows little emotion. She was adopted and raised by the Kocho sisters. As Shinobu's disciple, she used to call her Master, but after Shinobu woke up, she started calling her Shinobu-nee again.

Lost her parents to demons at a young age and was taken in by Shinobu and Kanae. She is currently in charge of chores like cooking at the Butterfly Mansion. She calls Shinobu 'Shinobu-sama'.

One of the young girls working as a nurse at the Butterfly Mansion. Like Aoi, she was taken in at a young age. She calls Shinobu 'Shinobu-sama'.

One of the young girls working as a nurse at the Butterfly Mansion. Like Aoi, she was taken in at a young age. She calls Shinobu 'Shinobu-sama'.

One of the young girls working as a nurse at the Butterfly Mansion. Like Aoi, she was taken in at a young age. She calls Shinobu 'Shinobu-sama'.

The protagonist of Demon Slayer. He calls Shinobu 'Shinobu-san'.

The Water Hashira of the Demon Slayer Corps. He calls Shinobu 'Kocho'. He is socially awkward and lacks communication skills. Among the Hashira, he is the closest to Shinobu. One of the Hashira who survived after the Final Battle. However, his right arm was severed.

The Wind Hashira of the Demon Slayer Corps. He calls Shinobu 'Kocho'. Because he loved Shinobu's sister, Kanae, he sometimes initiates conversation out of concern for Shinobu. He survived the Final Battle, but lost his right index and middle fingers. He uses very aggressive language.