Misaka 19999 (ミサカ19999号 Misaka Ichiman Kyūsen Kyūhyaku Kyūjūkyū-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 in Novosibirsk, Russia.