Reiko Kashima is a tall female yokai, easily towering over average size humans, with muscular arms and legs. Her most distinguishing feature, which is where her epithet comes from, is her extremely wide mouth with rows of multiple sharp teeth. She wears a heavy amount of makeup; mascara that accent her round eyes and lipstick for her mouth. Her nails are also colored dark. She has very long, jet black hair, which is kept tied with a bow, and wears a crown on her head. When absent of her makeup, Reiko Kashima's appearance drastically changes. Her head is nicely shaped, and her facial features are revealed to be less prominent to where she looks more human; having normal eyes with long eyelashes and, most noticeably, a normal lipstick mouth. Overall, her face outside of her makeup has been noted to be remarkably beautiful by Momo and Jiji.
After choosing to wear less makeup, Reiko Kashima's dress became slightly altered from when she spent her time searching for Momo, with the only change being the loss of her puffy sleeves. She also lost her crown.
The Slit-Mouthed Woman searching for Momo.
