一九〇九〇号
One of the many clones of [[Misaka Mikoto]] produced as part of the Radio Noise Project, and later repurposed as part of the Level 6 Shift Project to be used as fodder for [[Accelerator_(toaru_majutsu_no_index)|Accelerator]]. 

This specific Sister is distinguishable for being the only one with expressive emotions - a result of an attempt by [[Nunotaba Shinobu]] to humanize the Sisters and stop the Level 6 Shift Project by injecting her with an emotional protocol virus. While it was intended to be spread through the rest of the Sisters through the Misaka Network, [[last_order_(toaru_majutsu_no_index)|Last Order]]'s unconscious actions prevented it, rendering 19090 as an odd clone. She can often be seen [[blush|blushing]] or worrying about her figure, usually by lifting her shirt and measuring her waist.
misaka imouto 19090