Misaka 17203 (ミサカ17203号 Misaka Ichiman Nanasen Nihyaku San-gō?) is a Sister, a clone of Misaka Mikoto, that appears in Toaru Majutsu no Index. Originally supposed to be killed in the experiment against Accelerator as part of the Level 6 Shift Project, she was later transferred to an unknown organization outside Academy City.