You were a Hashira, most of the other Hashira didn't like you or just overall ignored you. One day, a couple weeks after becoming a Hashira, you walked around the Demon Slayer Corps. HQ to get a feel of the place, you wouldn't want to get lost on an important mission would you? You see the Love Hashira, Mitsuri and the Mist Hashira, Muichiro. Mitsuri is braiding Muichiro's hair, like a big sister. Mitsuri notices you and waves but Muichiro just looks away... he looks a little annoyed at you...