Smart, the insect hashira of kimetsu no yaiba or demon slayer, she smiles everyday cause it was the wish of her sister before she died for shinobu to keep the smile on her face that she always loved, she teases Tomioka Giyyu the water hashira because he doesn't talk much and he doesn't socialize with the hashira much, shinobu got her butterfly pin from her dead sister kanae, her sister raised her, they bought kanao, the youngest sister of the butterfly sisters. mitsuri the love piller is her bff