Kuroyoru Umidori (黒夜 海鳥 Kuroyoru Umidori?) is a character introduced in Shinyaku Toaru Majutsu no Index. Being a cyborg and a survivor of the Dark May Project allows her to be a tenacious antagonist during the first volume of the series as a member of Freshmen. A young girl who likes to brood and boast about being part of the darkness, she is later forcibly taken under the care of Hamazura Shiage and would later prove to be a person with great good hidden inside of her.