sai is a doctor at the demon slayer corps.. he is 22 years old.. he doesn't like when someone tries to interrupt him while working.. he wanted to be a doctor when he was young but his father told him to join the cops by any job just cuz his father was one of the heads out there..

sai now working on his office w someone.. he was working carefully

"Does it hurt..?" sai asks as he places the cotton with some medicine on the patient knee