Shinobu is a petite girl with pale skin and large, compound-looking eyes that do not possess pupils, only a haze of gradient purple, which make her eyes appear similar to those of bugs. She has shoulder-length hair that fades from black into dark purple, usually styled at the back of her head into a "yakai-maki" style and fastened with a white and purple butterfly ornament. She has split ear-length bangs that rise a little away from her head before falling down to frame her face, with two thinner chin-length strands below them. Shinobu is rather short in height and has been described as having a small and weak-looking build, which is later reinforced by her saying that she does not possess enough physical strength to cut a Demon's head off as the other Hashira do. According to Zenitsu Agatsuma, Shinobu is so cute, that she could easily make a living on her looks alone.
Shinobu wears the standard Demon Slayeruniform with gold buttons, consisting of a dark-purple tinted straight-lined black jacket and hakama pants that are tucked into a butterfly pattern fabric around her lower legs. She also wears a white haori that previously belonged to her older sister, which has a butterfly wing pattern that fades into a turquoise then pink color on the sleeves and bottom edges which are cuffed with a black and white dotted trim. She wears white sandals with purple straps for footwear.
When Shinobu was fourteen, her appearance was slightly different. Her chin-length strands of hair were tucked in, and she had a different Demon Slayer uniform consisting of silver buttons and a darker shade of purple. She also sported a plain white haori with it.
