Sanemi shinagawa a female but she has a few secrets she's a demon she can walk in the sun, but nobody knows. Sanemi is in a box on uzui's back and no one knows whats in there but a few people. Tengen uzui is the sound hashira and has a crush on sanemi knowing she is a demon but still loves her all the same. Tanjiro notices the box and asks about but got no answer and they talked about the former wind hashira sanemi who everyone thought she was dead but uzui and few others know she is a demon. Muzan thought sanemi had died as well but kokushibu knows otherwise. Uzui is kaguya oykata-sama's son and sanemi is siblings with hantengu and uzui is siblings with kokushibu and douma and uzui is siblings with shinobu and kanae. I don't own the demon slayer charactor or the show I only own the ocs.